This is part of our House MD Project series.

Click here to read the connection to the episode (spoiler alert!) On episode 3 of season 8 (named “Charity Case”), altruist millionaire Benjamin Byrd collapses in the street right after he donated a large sum of money to another foundation. The team argues wether his altruism is a symptom or not, and meanwhile he develops tachycardia (fast heartbeat) and his hands are shaking. When he offers to donate both his kidneys the presence of mental symptoms is obvious, and when understanding that his symptoms got worse after he received contrast media containing iodine, he is diagnosed with Plummer’s Disease. .

Danger level: Low

What is it?

In Plummer’s Disease (also known as Toxic Nodular Goiter), an area in the thyroid gland works with no control, and causes a state called hyperthyroidism – too much thyroid hormone in the blood.

Who gets it?

The disease is responsible for 15-30% of the hyperthyroidism cases. It usually develops in adults older than 50, and is more common in women. The disease is also more common in areas of the world where iodine deficiency is common.

What causes it?

As explained before about another disease which causes hyperthyroidism (Graves Disease), the thyroid gland normally produces thyroid hormone in response to a molecule called TSH that comes from the brain. In Plummer’s disease, an area in the thyroid gland (a nodule) starts producing thyroid hormone independently – without TSH. Such nodules are called toxic nodules – there is also such thing as non-toxic nodules, which don’t produce thyroid hormone or any other substance.

The disease is related to exposure to iodine (which is an important factor in the function of the thyroid gland).

How does it feel?

Plummer’s disease can cause symptoms that are related to hyperthyroidism and symptoms that are related to the presence of the nodules themselves.

• Hyperthyroidism can cause weight loss with increased appetite, frequent bowel movements, tremor, intolerance to heat, heart palpitations and a fast heart beat (tachycardia), hyperactivity and irritability and muscle weakness.
• If the nodule is large enough, you can see an enlargement of the gland called goiter, that looks like this:

This is a very large goiter (very rare today).

• Also, when the nodule is very large, it may compress other organs in the neck and cause problems with breathing and swallowing, and sometimes also hoarseness or voice changes.

How is it discovered?

First, the doctor will want to check if the level of thyroid hormone in the blood is high. This can be done by testing the levels of the hormone itself and also by checking the levels of TSH (which will be low).

Ultrasound of the thyroid gland can help recognize nodules in the thyroid (which look like balls in different sizes), and another test called thyroid scan can differentiate between toxic and non-toxic nodules. Sometimes the doctor will want to take a biopsy from the nodule to make sure that it’s not cancer.

How is it treated?

There are two ways to treat Plummer’s disease – the first one is to remove the toxic nodule in surgery (like on the House episode), and the second is to use radioactive iodine that is injected to the bloodstream, concentrates in the nodule and destroys it.

What happens after treatment?

Treatment usually cures the disease, but even when untreated the disease is usually not life threatening (though it’s not very pleasant to live with).

The bottom line – how do I avoid it?

Most of the time there is no specific way to prevent the disease. People with low levels of iodine in their blood are at risk for the disease, so it’s important to consume enough iodine in the diet. In the United States iodine is added to table salt and other foods so iodine deficiency in the diet is very rare.

Related posts:

1. Graves Disease – Why Some People Are Hyperactive For A Reason
2. Appendicitis – A Small Part of The Intestine That Can Cause Big Trouble
3. Hashimoto’s Thyroiditis – Do You Suffer From Weight Gain, Fatigue or Hair Loss? This Might Just Be The Cause

This is part of our House MD Project series.

Click here to read the connection to the episode (spoiler alert!) On episode 2 of season 8 (named “Transplant”), House treats the lungs of an 18-years old man who died in a motorcycle accident. The lungs were donated and planned to be transplanted in one of Wilson’s patients, but went bad just before the transplant, and House’s job was to find out what’s wrong with them. After ruling out cocaine abuse, a tumor in another organ (which affected the lungs) and even peanut allergy and heavy metal poisoning, House and his new and only team member find white blood cells in the lungs, and then diagnose the lungs with eosinophylic pneumonia

Photo by fox

Photo by FOX

Danger level: Medium

What is it?

Eosinophilic pneumonia is a group of diseases in which eosinophils (a type of white blood cells that are responsible for the body’s response in allergies and infections by parasites) accumulate in the lungs and interfere with their function.

Who gets it?

The disease isn’t common, but exactly how rare it is isn’t known. Different diseases in this group can be more common in men or women, and most of them develop in adults (usually not in elderly people).

What causes it?
Eosinophils are cells in our immune system that are active during allergic reactions and parasitic infections. When activated, eosinophils secrete chemicals that can cause inflammation. In people with eosinophilic pneumonia, eosinophils accumulate in the lung, are activated and secrete the chemicals – this causes the symptoms of the disease.
There are many causes for eosinophilic pneumonia. Some cases develop after the person is exposed to something outside the body – certain foods, drugs or even smoke (like in the House episode). Infections by parasites can also cause eosinophilic pneumonia. In other cases, the disease is related to changes inside the body – for example, it can be associated with another disease process. In some cases the reason for the disease is unknown.

An eosinophil, as seen under a microscope. Photo by Akay Miller

How does it feel?

The symptoms can be mild or severe, and include cough, wheezing and shortness of breath. When the disease is severe, it can cause the rate of oxygen in the blood to decrease and sometimes respiratory failure develops.

How is it discovered?

The doctor will suspect eosinophilic pneumonia if symptoms appeared shortly after exposure to foods or drugs that can cause the disease. Tests are performed to approve the diagnosis: blood tests to search for an elevated number of eosinophils in the blood; chest x-ray to see signs of pneumonia, and microscopic examination of lung secretions to search for eosinophils there as well.

How is it treated?

Usually, eosinophilic pneumonia is treated with steroids. If the disease appeared after exposure to foods or drugs – avoiding them will help with recovery, and if the disease is due to a parasitic infection – antibiotics are required.

What happens after treatment?

Most cases respond to medications (or even get better without treatment at all), but sometimes there’s severe lung failure which can be life threatening.

The bottom line – how do I avoid it?

If the disease appeared after exposure to a certain food or drug, avoiding them may prevent the disease from recurring. Also, people who had an attack of the disease should seek medical help right away if symptoms come back.

Related posts:

1. Your Questions Answered – Asbestosis – What Work Exposure Can Do To Your Lungs
2. Pleural Mesothelioma – Cancer of The Lungs Caused by Exposure to Asbestos
3. Deep Vein Thrombosis – Clots in Your Veins Which Can Travel To Your Heart and Lungs

This is part of our House MD Project series.

Click here to read the connection to the episode (spoiler alert!)

On the first episode of season 8 (named “Twenty Vicodin”, and featuring an interesting guest in the cast!), House is in prison after crashing his car into Cuddy’s living room. One of the prisoners has a fever, joint pain and a rash on his thigh, and House convinces the prison’s doctor that he has lupus. Later, after the prisoner breaks his arm from a minor hit and doesn’t stop bleeding from a small cut, House listens to his chest and discovers an “acoustic shadow”, meaning there is a mass in his lungs. After drinking some coffee the prisoner develops a severe allergic reaction (anaphylaxis) which causes his airway to swell up and almost kills him. House then realizes that the reason for the reaction was the high temperature of the coffee and diagnoses him with mastocytosis

Photo by fox

Danger level: Medium

What is it?

Our immune system is composed of many types of cells and partןcles. Mast cells belong to the immune system and are involved mostly in allergic reactions. These cells produce substances that cause some of the allergy symptoms, the most famous of them is histamine. In systemic mastocytosis  the amount of these mast cells increases significantly, causing the disease.

This is how a mast cell looks. Photo by Ed Uthman

Who gets it?

Systemic mastocytosis is an extremely rare disease – so rare that it’s frequency in the population is not known. It’s a bit more common in men than women, and appears mostly in children, though it may happen to adults (and then the most common age is 55).

What causes it?

The disease develops when a mast cell starts dividing uncontrollably (like in cancer). Since the mast cells keep dividing, there are too many of them – and they can form a tumor, circulate in the blood or accumulate in organs. Also, substances that mast cells produce like histamine are released in larger amounts than usually. All these processes can cause symptoms.

How does it feel?

Symptoms can appear in any organ where mast cells accumulate. This can cause skin rashes, bone pain and problems with the liver, spleen or bone marrow.

Substances that are produced in mast cells and released in large amounts (like histamine) can cause itching, flushing and symptoms in the digestive system (for example: abdominal pain, diarrhea, peptic ulcers and problems with the absorption of food).

Another important symptom is severe allergic reactions (also called anaphylaxis) which can be dangerous and cause difficulty breathing or a very low blood pressure. The most severe allergic reaction in mastocytosis is to bee stings.

In some cases flushing and low blood pressure can develop in response to certain drugs against inflammation (like in the “aspirin test” at the end of the episode), and any symptom can be worsened by these drugs, alcohol or narcotics.

Mastocytosis in toddlers

How is it discovered?

The doctor can suspect mastocytosis based on the symptoms and blood work, but the only definitive test is a bone marrow biopsy, in which a bone sample is taken from the lower back. An important test which can support the diagnosis before performing the biopsy is measuring the levels of histamine in the blood or urine.

How is it treated?

There is no cure for mastocytosis. Treatment is aimed at reducing symptoms, and this is done mostly by different types of pills (for example, anti-histamines which are usually used for allergies).

What happens after treatment?

There are different types of mastocytosis which are dangerous in different levels. In some cases patients have the same life expectancy as the normal population, but in the more violent types (which are, luckily, more rare) patients survive for several months only.

The bottom line – how do I avoid it?

Unfortunately, there is no known way to avoid mastocytosis.

Related posts:

1. Sickle Cell Disease – When the Shape of Your Blood Cells Can Kill You (As Seen On House MD)
2. Astrocytoma (Butterfly Tumor)–A Brain Tumor That Spreads To Both Sides (As Seen On Grey’s Anatomy)
3. Pheochromocytoma – A Rare Tumor That Can Cause Hypertension (As Seen on House MD)

This is part of our House MD Project series.

Click here to read the connection to the episode (spoiler alert!)

Photo by Fox

Photo by Fox

Danger level: Medium

What is it

Syringomyelia is damage to the spinal cord caused by a fluid-filled area (a cyst, which is called a syrinx). The syrinx usually appears first in the neck, and later extends upwards or downwards – putting pressure on other areas of the spinal cord.

Who gets it

Syringomyelia is not common – the frequency in the US is 8.4 cases per 100,000 people. The disease usually appears around the ages of 20-40, and men get it more than women.

What causes it

The fluid inside the syrinx is called Cerebro-Spinal Fluid (CSF) – this fluid can be found normally around and inside the brain and spinal cord. A syrinx is formed when there is a problem with the circulation of this fluid so there’s too much of it in a specific area inside the spinal cord. This might happen for several reasons, including birth defects (which are the most common reason), trauma to the spinal cord (like in the House episode), a tumor in the spine or inflammation of the spine.

How does it feel

The symptoms usually develop slowly and appear gradually:

• Muscle problems, including muscle weakness in the arms and legs, loss of muscle mass and contractions or  muscle-spasm in the legs.
• Sensory problems – decreased sensations (of pain, temperature and touch), numbness or pain. These problems are more common in the neck, shoulders, arms and trunk (a “cape-like” pattern).
• Headaches.
• Problems with bowel and bladder function.

How is it discovered

If you have symptoms of syringomyelia, the doctors will start with a neurological exam (checking muscle strength and sensation) which will help them to estimate where the problem which causes the symptoms is located. In order to prove that there is a syrinx and show it, the doctor will perform an MRI of the spinal cord.

An MRI of syringomyelia. The syrinx is the white area inside the gray spinal cord. Photo by Cyborg Ninja

How is it treated

When there are symptoms, the treatment is surgery to drain the fluid from the syrinx. Sometimes a tube is inserted for continuous draining. After surgery, physiotherapy can help restoring function in the damaged muscles. If there are no symptoms, treatment is not necessary.

What happens after treatment

The surgery stops the progression of the syrinx so new symptoms will not appear. Also, about half of the patients report significant improvement in the symptoms they had.

Without treatment the disease gets worse and worse and eventually causes severe disabilities.

The bottom line – how do I avoid it

There is no way to prevent syringomyelia – the most important thing is to catch it on time before the symptoms cause disabilities.

Related posts:

1. As Seen on Grey’s Anatomy – Tethered Spinal Cord Syndrome
2. As Seen on Grey’s Anatomy – Normal Pressure Hydrocephalus (NPH)
3. Teratoma–When You Can Find Teeth and Hair Inside Your Body (As Seen on House MD)

This is part of our House MD Project series.

Click here to read the connection to the episode (spoiler alert!)

On episode 2 of season 7 (named “Selfish”), Della Carr collapses during indoor skating for a charity event for her brother’s disease – muscular dystrophy (which causes muscle weakness). Apparently she had an arrhythmia (problem with her heart rate). While the team prepares her for a test to see if she has a syndrome that causes arrhythmias, they find out she stopped producing urine, which means her kidneys are failing. Later she also starts to cough blood, and a lung biopsy finds she has a lung disease called LAM. She undergoes a lung transplant but the new lung is failing soon afterwards. After House talks to her brother, he reveals that for a year she had non-specific symptoms like ear pain, chest pain, hoarseness and a runny nose. He then diagnoses her with sickle cell trait.

[house 702 photo]

Photo by Fox

Photo by Fox

Danger level: Medium

What is it?

Sickle cell disease is an inherited disease which affects our red blood cells. It causes them to stick to each other and interrupt the blood flow in small vessels, so less blood gets to the organs.

Who gets it?

Sickle cell disease is a genetic disease, meaning that people inherit it from their parents. There is a defective gene in the disease (called “hemoglobin beta-chain”). When a person gets two defective copies passed on from their parents (one from the mother and one from the father) they are sick and have sickle cell disease. If they only inherit one copy (from their father or mother) they are carriers, and their condition is called sickle cell trait.

Sickle cell disease isn’t very rare – one out of 625 people in the United States has the disease.

It’s much more common in Afro-Americans – 8% have the sickle cell trait, compared to only 0.24% of white people. It’s also common in Africa, Greece, Turkey and India.

It can affect men and women alike.

What causes it?

Our red blood cells carry oxygen and bring it from our lungs to organs in our body. It’s necessary for them to survive. The molecule in the red blood cells that’s responsible for carrying the oxygen is called hemoglobin.

The defect in the gene in sickle cell disease causes hemoglobin to be distorted, meaning the red blood cells get distorted as well. They look like a sickle (hence the name of the disease).

Normal and distorted red blood cells. Photo by NIH.

This causes the red blood cell to be sticky. The red blood cells stick to each other inside small blood vessels and clog them, and so less blood gets to the organs.

How does it feel?

Symptoms of sickle cell disease usually start when the baby is 6 months old. They include:

• Pain attacks (crises): This is the most common symptom. The pain can appear in the abdomen, bones, joints, and soft tissue. Each attack lasts for hours-days, it stars and ends suddenly. These crises are most common in small children . Some patients have lots of them and others have only a few or even none at all. Sometimes pain is accompanied by fever or general discomfort.
• Hand-Foot Syndrome: Swollen and painful hands and feet. This lasts 1-2 weeks and is common in very small children (6-18 months).
• Acute Chest Syndrome: Chest pain, fever, cough and difficulty breathing. This is a medical emergency, and if untreated can cause severe breathing problems and even death. It can happen in children and adults.
• Damage to internal organs: This happens when less blood gets to an organ- that organ might stop working. It can happen in many organs, like kidneys, liver and lung. When this happens in the brain, it can cause a stroke – 30% of the children with sickle cell disease have at least one stroke. When it happens in the spleen repeatedly, it causes it to stop working, and since the spleen is part of our immune system, this can cause frequent infections which can be life-threatening.
• Anemia: Sickle cells tend to break down and die, so there are less of them. Anemia causes paleness, weakness, difficulty in exercise and might cause a delay in growth and puberty. Since the anemia is chronic, most patients get used to it and don’t have a lot of symptoms.
• Jaundice: This is a yellowish shade of the skin and the white part of the eyes. It’s caused by the breaking down of sickle cells.

This video explains the disease and its symptoms.

How is it discovered?

A blood test can discover if there is an abnormal hemoglobin molecule in the blood. A genetic test can also be done, which tests for the bad gene. A genetic test can also be done during pregnancy, so it can be found if the baby will have the disease.

How is it treated?

The treatment focuses mainly on treating the symptoms and preventing pain crises – things such as treating infections with antibiotics, easing the pain with pain killers, etc. Also, a drug called hydroxyurea can help. It causes the body to create a different type of hemoglobin, which helps.

What happens after treatment?

The treatment isn’t meant to cure the disease but to help with the symptoms. The life expectancy in sickle cell disease is around 50-60 years, and the most common causes of death are organ failure (especially kidney) and infections.

And what about sickle cell trait? This is when only one copy of the gene is defected, and less then a half of the hemoglobin is distorted. They usually live normally without any symptoms, except in rare cases (like on the House episode).

The bottom line – how do I avoid it?

If both parents have the sickle cell trait or the disease itself, it’s important to perform a prenatal test as explained before.

People who have sickle cell disease already can sometimes avoid the pain crises: drink enough water (to avoid dehydration), avoid smoking and high altitudes (which cause a decrease in the level of oxygen in the blood), avoid cold places, and when exercising rest frequently and drink a lot.

Related posts:

1. Mastocytosis – It’s Not A Tumor, But Its Growth in Your Body Can Kill You (As Seen On House MD)
2. Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency – When Certain Conditions Can Destroy Blood Cells
3. Behçet’s Disease – Inflammation of Your Blood Vessels, Throughout the Body (As Seen on House MD)

This is part of our House MD Project series.

Click here to read the connection to the episode (spoiler alert!) On episode 1 of season 7 (named “Now What”), the hospital’s only neurosurgeon, Dr. Richardson, has a severe nausea which doesn’t respond to strong anti-nausea drugs. The team treats him with stronger medications for his nausea – it passes but he starts to hallucinate and behave oddly. At first, the team thinks his behavior is a side effect of the drugs they gave him and test for a bunch of diseases like hepatitis and peptic ulcer. Only when they start to think of his behavior as a new symptom, and after they find out he was at a sea-food festival several days before, they diagnose him with toad egg poisoning

[Photo from episode]

Photo by Fox

Danger Level: High

What is it?

The poison in toad eggs is the venom of the Cane Toad. The venom is usually located in the salivary glands of the frog and on the skin, and rarely it can also pass to the eggs. The toad venom is also used in Chinese medications, so consuming these medications might also cause poisoning: it is the main ingredient in a medicine called Chan-Su which is used mostly as a topical aphrodisiac (and was banned from the Uniter States after four men died after trying to swallow it), and is also an ingredient of Kyushin, which is used in Chinese medicine to treat heart problems.

What causes it?

The toad poison contains a substance called Bufotenin, which is very similar to a cardiac medication called Digoxin (used to treat heart failure and certain abnormal heart rhythms). Digoxin can be toxic in high doses, and the toad venom causes symptoms similar to an overdose.

How does it feel?

The venom of the toad causes several symptoms:

• Nausea with vomiting and possible abdominal pain.
• Cardiac symptoms – mostly problems with the heart rate (which are called arrhythmias), which can be deadly. You might feel heart palpitations.
• Mental symptoms, such as hallucinations. The cane toad is also known as the “hallucinogenic toad” – licking its skin can cause hallucinations which last for about an hour. However, mental symptoms are less described in toad venom poisoning.

Photo by Doug Greenberg

How is it discovered?

The doctors will suspect this if there is a story of eating certain foods such as toad soup, toad cake or toad eggs, or if the patient uses one of the Chinese medications mentioned above. They will test your blood for potassium levels (if it’s high – this is usually a bad sign, since it may cause the heart rhythm problems mentioned above) and for the level of Digoxin (this test can also identify the poison). They will also do an ECG to look for problems with the heart rate.

How is it treated?

There is an antibody for Digoxin which can be used to treat toad venom poisoning as well and has been proved to save lives. Besides that, the treatment focuses on stopping the symptoms.

The bottom line – how do I avoid it?

It’s important to be aware of the possibility of poisoning, and seek medical help if you start feeling nausea or have heart palpitations after eating foods which contain toad. Also, avoid topical aphrodisiacs containing Chan-Su, which are marketed as “Rockhard”, “Love Stone”, or “chan su” – and are forbidden to import to the United States.

Related posts:

1. Radiation Poisoning– What it Can Do To You (As Seen on House MD)
2. Organophosphate Poisoning – Getting Poisoned by Pesticides (As Seen on House MD)
3. Naphthalene Poisoning – When Mothballs Kill More Than Just Moths (As Seen on House MD)

This is part of our House MD Project series.

Click here to read the connection to the episode (spoiler alert!)
On episode 23 of season 7 (the season finale, named “Moving On”), Afsoun Hamidi, a performance artist, collapses during filming one of her projects. Later she has pancreatitis, something resembling a tumor in her brain, and a skin rash. Biopsy of the rash reveals that her symptoms are related to a condition called Wegener’s granulomatosis.

Photo by NBCUniversal

Danger level: High

What is it?

Wegener’s Granulomatosis (WG for short) is an inflammation of blood vessels, restricting blood flow to various organs in the body.

Who gets it?

WG is quite rare. In the United States, for example, it’s estimated that about 3 out of every 100,000 people are sick with it. It’s more common in people of Northern European origins, and is less common in black people. It can occur in any age, but is most common in middle age (the average age when it appears is around 40). Men and women are affected equally.

What causes it?

In WG there is an inflammation of blood vessels in the body, meaning it’s a vasculitis (the medical term for inflammation of blood vessels. There are other diseases in this group – such as temporal arteritis and kawasaki, which we covered before).

Our blood vessels generally come in 3 sizes, much like clothing. Small, medium and large. WG is an inflammation of small and medium sized blood vessels.

It happens because the body actually attacks its own blood vessels. The process isn’t completely understood, but probably involves a change in the body’s immune system which triggers the body destroying its own blood vessels.

WG tends to affect mostly 3 systems in the body: The upper airways, the kidney, and the lungs. They are affected since the arteries that supply them with blood are damaged in the disease.

How does it feel?

There are some general symptoms in WG which include loss of appetite, fever, fatigue, and even weight loss.

Usually the first specific symptoms involve the upper airways and can include nosebleeds, nasal congestion, collapse of the bridge of the nose (causing a deformity called saddle nose, seen in this picture), a hole in the nasal septum (which separates our right side of the nose from the left), inflammation of the sinuses (sinusitis), ear infections, difficulty breathing, and coughing (sometimes a bloody cough).

When the disease is in the lungs people may feel shortness of breath (which may be caused by bleeding in the lungs), or cough. When the kidneys are involved, kidney failure can occur, which may be life threatening.

Other organs may be involved, such as the skin (a rash may appear, like the one on House), the joints – which can become inflamed as well, and the nerves (something which can also affect vision – like the patient on House told that had happened to her).

Believe it or not, but there are even more possible symptoms, into which we won’t get here (including, rarely, pancreatitis, which for some reason was a main manifestation on House).

How is it discovered?

The disease resembles many other diseases, making the diagnosis difficult. A blood test checking for a component in the body called ANCA can be used, since it’s elevated in the disease. A physical exam, x-ray, and urine test, among others, can help with the diagnosis. The definitive way is performing a biopsy (taking a piece of an organ to look at under a microscope) on one of the involved organs, which will show something like this:

WG under a microscope. The round area on the left is called a granuloma, which is a mass of immune cells (that’s how the disease got its name). Photo by Nephron.

How is it treated?

Drugs that suppress the immune system (which attacks the body here) are used in WG. This includes steroids and chemotherapy.

What happens after treatment?

With treatment given on time, symptoms may disappear altogether. Still, in about half of patients, the disease may return. Before the disease was understood and the right treatments were given, about half of all patients died within 5 months. Today more than 75% get to live longer.

The bottom line – How do I avoid it?

Unfortunately, there is no known way to prevent WG.

Related posts:

1. Behçet’s Disease – Inflammation of Your Blood Vessels, Throughout the Body (As Seen on House MD)
2. Waldenström’s macroglobulinemia – A Rare Blood Cancer That Can Lead To Strokes
3. Peripheral Arterial Disease – A Narrowing of Blood Vessels that Will Shorten Your Life

This is part of our House MD Project series.

Make sure to tune in tomorrow for a medical recap of tonight’s finale!

Click here to read the connection to the episode (spoiler alert!)


On episode 22 of season 7, named “After Hours”, a woman named Darrien is bleeding after a stabbing to her body. Her blood pressure and heart rate are almost missing on one side of her body, meaning something is blocking one of the arteries there. She then starts hallucinating due to an interruption of blood flow to her brain. Fever also develops, hinting at an infection. Turns out her symptoms were due to an infection with entamoeba, a parasite, which was released to her bloodstream by the stabbing.

Photo by NBCUniversal

Danger level: Medium

What is it?

Entamoeba histolytica is a parasite which can infect humans. It can infect the large intestine and sometimes the liver and other organs, causing a condition called amebiasis.

Who gets it?

It’s estimated that about 10% of the world’s population are infected with Entamoeba histolytica. It’s more common in some areas of the world where sanitation is poor, such as Central and South America, Africa, and Asia. In the United States it is estimated that about 4% of the population are infected – most of them are immigrants or people who have traveled to countries where it’s more common.

What causes it?

The infection, as mentioned above, is caused by a parasite – an ameba named Entamoeba histolytica, seen under a microscope in this photo:

The parasite can exist in 2 forms: One active (called a trophozoite) and one dormant – called a cyst. Infection occurs when a person swallows cysts. They hatch in the body, releasing trophozoites. These in turn start multiplying and can cause wounds in the lining of the intestines. They can also spread to the liver and other places.

Some trophozoites become cysts again, and are excreted in the feces, helping the infection spread.

Now how do people actually get to swallowing the parasite, or how do they infect themselves? The cysts can spread from person to person or through food or water. In places where there is poor sanitation, food and water can be contaminated with feces containing the ameba. If soil is polluted by human feces, fruits and vegetables growing in it will be infected as well. If someone doesn’t wash hands properly after going to the toilet, the infection can spread. You’re getting the idea…

How does it feel?

In many people (about 80%), the infection isn’t felt at all. When it is felt, symptoms start within about 2-4 weeks of ingesting the parasite, and can include flatulence, abdominal pain, diarrhea, or constipation. In some cases a dysentery may be caused, meaning there is blood and mucus in the feces. Fever may also develop. Blockage as well as perforation of the intestines can occur.

Sometimes the ameba may spread to the liver, causing an abscess (a localized collection of pus). The person would feel fever and chills, sweating, nausea and vomiting, and weight loss. Rarely, the ameba can spread to other areas of the body (even the brain).

This vivid video sums it up:

How is it discovered?

A stool sample has to be examined to find the ameba. Sometimes a tube with a camera (colonoscope) can be inserted to the colon to collect a sample from a wound caused by the ameba, to look at under a microscope.

To find a liver abscess, an imaging method such as an ultrasound, CT or MRI can be used. Blood tests can also help with the discovery of the parasite.

How is it treated?

An antibiotic is given that can kill the ameba. An example of such a drug is metronidazole (which was mentioned on House).

The bottom line – How do I avoid it?

When travelling to an area known to have poor sanitary conditions, make sure to drink only bottled water, tap water that’s been boiled for at least 1 minute, or bubbly water or soda drinks from sealed cans.

Do not drink fountain drinks or any drinks with ice cubes. Do not eat fresh fruit or vegetables you didn’t peel yourself. Do not eat dairy products that may not have been pasteurized. And don’t eat anything sold by street vendors.

If you have been infected, you can minimize risk of infection to others by washing your hands with soap and water after using the toilet, after changing diapers, and before handling food.

Related posts:

1. Malaria – A Deadly Infection Passed On By Mosquitoes (As Seen on House MD)
2. Gas Gangrene – An Infection That Can Rapidly Kill Your Muscles (As Seen on House MD)
3. Common Variable Immunodeficiency (CVID)–When a Cold Can Threaten Your Life (As Seen on House MD)

This is part of our House MD Project series.

Click here to read the connection to the episode (spoiler alert!)


This episode (episode 21 of season 7, named “The Fix”) is a little tricky, since there were two major diseases here. First, Wendy Lee, a weapons designer, has a seizure, abdominal pain, inflammation around the kidney, a heart attack, rectal and vaginal bleeding, burning and bleeding gums and swollen genitals. She was poisoned with Spanish Fly (containing cantharidin, a toxin). The other story involved a boxer who passed out way too early during a fight. House discovers he has a glomus tumor in the back of his neck, which when pressed during the fight caused him to collapse.
We’ll be more brief about each condition here, since there are two of them.

Photo by FOX

Spanish Fly

It all starts with a green beetle called the Spanish Fly, pictured below.

Photo by Franco Christophe

The beetle contains a material called cantharidin. The beetle is usually crushed into powder form, which has many uses. One of them is getting farm animals to mate.

Throughout history, it’s also been used as a means of keeping an erection. This happens since, when it’s excreted in the urine, it causes swelling of the genitals (like was seen on House), and also an erection.

Another use is as an aphrodisiac (a substance that increases sexual desire).

Unfortunately, if the concentration of catharidin isn’t low enough, more than sexual arousal can occur – it can lead to actual poisoning.

How does it feel?

Catharidin poisoning can lead to burning of the mouth, pain while swallowing, nausea, vomiting blood, urinating blood, and painful urination. It can lead to bleeding of the upper gastrointestinal tract and its erosion. It can damage the kidneys. It can also, as was seen on House, lead to seizures and to problems with the heart. And last but not least, it can lead to an uncontrollable erection.

How is it treated?

There is no antidote. The only way to treat someone poisoned with Spanish Fly is through supportive treatment, which means treating the various symptoms.

Glomus Tumor

These are rare tumors belonging to a group of tumors called paragangliomas. Those of you with good memories will recall that we’ve also featured an article about a disease called pheochromocytoma, which usually occurs in the adrenal gland. When it occurs outside the gland, it’s called a paraganglioma.

When paragangliomas occur in the area of the base of the skull they are called glomus tumors.

And how does this all come together?

Pheochromocytomas, and paragangliomas, are tumors that secrete substances called catecholamines (such as epinephrine). When these are secreted, they can lead to hypertension, headaches, palpitations, sweating, nervousness, and even weight loss (the boxer on the House episode was so overworked when his tumor was pressed and released these substances, that he has lost consciousness).

Photo by mitopencourseware

How is it discovered?

The tumor can be discovered by taking a urine sample for catecholamines, which will be higher than normal. A CT, MRI, or other form of imaging technique can discover where in the body the tumor is located.

How is it treated?

The tumor is usually taken out in surgery, although in some cases radiation therapy is used.

Related posts:

1. Sleeping Sickness – A Fly Bite That Ends in A Coma (As Seen on House MD)
2. Carcinoid Tumors – A Rare Tumor Often Not Found On Time
3. Nesidioblastoma – A Tumor of the Pancreas That Can Secrete Hormones (As Seen on House MD)

This is part of our House MD Project series.

Click here to read the connection to the episode (spoiler alert!)


On episode 19 of season 7, called “Last Temptation”, a 16 years old patient named Kendall Pierson collapses while embarking on a boat trip. Later her hand turns blue while running on a treadmill and her pineal gland is found to be calcified. Later she collapses due to a hypertensive crisis. An MRI of her arm discovers that she has a tumor called lymphoid sarcoma in the arm. As hard as we tried, we couldn’t really find enough data about lymphoid sarcoma. Seems the writers went a little too rare with the disease, or that a more likely diagnosis is in place here: osteosarcoma.

Photo by NBCUniversal

Danger level: High

What is it?

Osteosarcoma is the most common type of bone cancer is children.

Who gets it?

In the United States, about 400 children  and adolescents (under age 20) are diagnosed with osteosarcoma each year. 

It’s a little more common in black people and in males. It’s also more common as a child ages – quite rare under the age of 5, but becoming more common towards age 20 (it’s more common at the age when a child is growing faster).

What causes it?

The exact reason for the development of osteosarcoma isn’t known. There are, though, some risk factors which increase a child’s risk of developing the tumor:

1. Rapid bone growth: As mentioned above, at times when the child grows faster, their chances of developing an osteosarcoma increase.
2. Exposure to radiation
3. A genetic problem: For example, children with retinoblastoma (more on that in a future post) are more likely to develop osteosarcoma. (other genetic diseases associated with it include Li-Fraumeni syndrome, and Rothmund-Thomson syndrome – more on those in the future).

How does it feel?

Any bone may be involved in the disease, but it’s more common in areas of bone which grow faster, such as the end of the thigh bone, the beginning of the shinbone, or the beginning of the arm bone.

Usually the child will feel pain in the area, and a swelling may also be felt there. Sometimes the child may limp as a result of the pain.

How is it discovered?

Usually an x-ray is performed first on the area. It will show an area of destroyed bone (called in medicine a “lyric lesion”). An example for that can be seen in this x-ray.

Photo by bc the path

In order to diagnose osteosarcoma for sure, a piece of the bone is needed (a process called a biopsy). It is then looked at under a microscope. This is how it looks:

There are many types of cells in this picture, which we can’t explain here. There is also a clear pink area, created by the tumor. Photo by Nephron.

CT and/or MRI are usually also needed, to see if the tumor has spread to other areas in the body (it tends to spread to the lungs and to other bones).

How is it treated?

Osteosarcoma is usually treated with chemotherapy, after which surgery is performed, which either removes the tumor or involves an amputation of the limb in which the tumor exists (like the case on the House episode). After that, more chemotherapy is usually used.

What happens after treatment?

The most important way to answer that depends on whether the tumor has spread to other areas, a fact which worsens the outcome.

About 60-70% of children with a tumor that hasn’t spread are cured thanks to treatment. Those with metastasis have a worse outcome – only 30-35% of them will survive.

There is currently no known way to prevent osteosarcomas.

The following video is about Bianca Bresadola, who died of osteosarcoma. May she rest in peace.

Related posts:

1. Neuroblastoma – The Most Common Cancer in Infants
2. Paget Disease of Bone – Bone Deformity For An Unknown Reason
3. Necrotizing Fasciitis Revisited, Osteosarcoma, and Aneurysms – (As Seen on House MD)