Hookworm Disease Explained

Hookworm Disease Explained

The typical tortuous skin lesions of hookworm disease are aptly known as skin moles. Fortunately, the extremely unpleasant disease has good chances of recovery and can be avoided with a little caution.

What is hookworm disease?

Hookworm disease is caused by different genera of hookworm larvae. The most common pathogens are the species Necator americanus, Ancylostoma duodenale, both only found in humans, and Ancylostoma brasiliense, the dog hookworm.

Other names for the condition include skin mole, creeping eruption, pit disease, ankylostomiasis, and larva migrans. It is one of the most common skin diseases in tropical and warm regions. Hookworms live in Asia, Africa, the Caribbean, and Central and South America. The worms can also occur in the Mediterranean region when it is very hot.

The disease was first mentioned in writing in 1874, and in 1928 it was assigned to specific pathogens. The skin mole is particularly common in mine and tunnel workers, which is why it is considered an occupational disease for them.


When hookworm larvae burrow into a person’s skin, hookworm disease develops. Infection usually occurs when a person walks barefoot on soil contaminated with hookworm-infested animal and human feces, for example on a bathing beach.

Diseased animals and humans excrete hookworm eggs with the faeces, which develop into larvae within a few days. These can survive two to three weeks without a host. The disease can also be triggered by food contaminated with hookworms. But this case is rather rare.

Human-to-human transmission can be ruled out. Skin moles are changes in the skin that form when the larvae crawl under the skin.

Symptoms, Ailments & Signs

Just a few hours after the larvae have penetrated the skin, hookworm disease and skin moles can become noticeable through redness and itching . If the hookworm larvae migrate into the lungs or larynx, those affected feel coughing or nausea, hoarseness and shortness of breath.

Colonization of the digestive tract becomes noticeable about one to four weeks after infection with nausea, vomiting, abdominal pain, loss of appetite and flatulence, these symptoms are usually accompanied by bloody-mucous diarrhea.

A severe infestation can also result in anemia, which is characterized by general weakness, a drop in performance, difficulty concentrating, headaches and noticeable pallor of the skin. Other symptoms can include hair loss and brittle nails.

In general, hookworm disease weakens the body’s defense system and makes it more susceptible to infections. Due to the loss of protein associated with the disease, more water often accumulates in the tissue ( formation of edema ).

The skin mole, caused by the larvae of dog and cat hookworms, stays just under the skin without penetrating deeper organs. In the early stages, the parasites trigger quite unspecific skin changes such as redness and swelling. As the larvae begin their migration, their burrows appear as red, winding lines that can lengthen by about an inch per day. The associated itching is described as very strong to almost unbearable.

Diagnosis & History

The diagnosis is usually made quickly due to the typical skin changes. They are tortuous, reddish, thin ducts that form under the skin. Examination of the stool can also reveal hookworm eggs under a microscope.

First, there is severe itching at the site of the skin changes, especially at the entry point of the larva. After the larvae have burrowed under the skin, they reach the lungs and intestines via the bloodstream. Pathogens in the lungs trigger strong coughing stimuli. In the intestine, the larvae begin to develop into adult worms. That takes about a month.

The larvae attach themselves to the mucous membrane of the small intestine and suck blood, which results in severe blood loss and possibly even anemia. One to four weeks after infection, other symptoms such as nausea and vomiting, abdominal pain, flatulence, mucous-bloody diarrhea, loss of appetite and, in particularly severe cases, signs of bronchitis appear.

The larvae of the dog hookworm cause severe itching skin irritations, but they disappear after a few weeks because they cannot survive in human skin.


With these diseases, in most cases, there are very unpleasant ailments on the skin, which can severely limit the patient’s life and reduce the quality of life. In most cases, itching and redness develop on the skin. These can negatively affect the patient’s aesthetics and lead to reduced self-esteem or inferiority complexes.

Furthermore, anemia occurs, which has a very negative effect on the health of the patient. Those affected suffer from severe abdominal pain and vomiting and nausea. It is not uncommon for diarrhea and flatulence to occur, with bloody stools often triggering panic attacks. The patients also suffer from a loss of appetite and can therefore show signs of deficiency.

If the pathogens also spread to the lungs, this can lead to a strong cough and inflammation of the airways. As a rule, these diseases can be treated relatively easily, so that there are no further complications and symptoms. This is where medications are used. Life expectancy is not reduced with successful treatment.

When should you go to the doctor?

If you notice swelling, ulcers, or bumps on the skin, you may have a skin mole. A doctor’s visit is advisable if the symptoms persist longer than usual or other symptoms appear. If symptoms such as itching, discoloration of the skin or open wounds occur, medical advice is required. At the latest when inflammation occurs, the affected person should go to the family doctor. This can diagnose the hookworm disease and initiate further measures.

Accompanying symptoms such as diarrhoea, nausea and vomiting require medical care if they persist over a period of several days or weeks. Serious complications such as persistent abdominal cramps, severe flatulence or high fever must be clarified immediately. The same applies to lesions under the feet, blood in the stool or dysfunction of the limbs. If the symptoms mentioned occur after contact with a possibly infected animal or after visiting a bathing beach, the suspicion of a skin mole is obvious. In this case, it is best to talk to your family doctor.

Treatment & Therapy

Hookworm disease can be effectively treated with anti-worm medication. Ivermectin, albendazole and thiabendazole have proven to be effective agents. They are applied topically or taken orally, depending on where the larvae are located.

Oral intake is only carried out if there is no improvement after a week of external treatment, since it is associated with many side effects. The antiworm drugs paralyze the muscles of the larvae so that the body’s immune system can fight and eliminate them more easily.

Severe accompanying symptoms such as diarrhea and vomiting can also be alleviated with appropriate medication. Cooling and soothing creams and ointments reduce the itching. Surgical measures or freezing have not proven to be very effective.

Outlook & Forecast

The prognosis for hookworm disease and skin mole is favorable. Spontaneous healing occurs in most patients after a few days or weeks. The symptoms heal completely. Normally, there are no consequences or impairments to be expected.

More than 80% of the pathogens die off on their own if the patient’s immune system is intact and are then transported out of the organism. The treatment often consists of treating the affected person symptomatically, since the pathogens have already been deactivated by the body’s own defense system and no longer pose a threat.

During the course of the disease, hookworm disease can lead to serious and life-threatening complications in some risk groups. Children in particular need adequate medical care if they lose a lot of blood. They are at increased risk of mortality if left untreated. In addition, there is a risk of further infections developing, which must be minimized.

If other diseases develop, the otherwise good prognosis deteriorates considerably. The hookworm disease and the skin mole demand a lot of resources from the organism, so that the patient experiences a significant deterioration in the general state of health in the event of a further infection. In severe cases, the internal forces are not sufficient and there are permanent impairments or a shortening of the existing life expectancy.


There is currently no vaccination against hookworm, but it is in the development phase. However, there are some measures to prevent hookworm disease: If you are in a tropical or hot region, you should not walk barefoot but wear sturdy shoes. Pads and loungers on bathing beaches could be contaminated by animal or human droppings and should be avoided.

Playgrounds and sandpits are other dangerous spots, as they may be contaminated with animal droppings. They should therefore be cleaned regularly. Regular and careful deworming and delousing of pets is also part of the preventive measures. Anyone who is already infected should only use toilet facilities and not defecate outdoors.


Usually, no follow-up care is required when treating hookworm located in the intestine. They respond well to drug therapy and die quickly. However, it is different with hookworms, which have not taken the usual route to the intestines but have settled in the skeletal muscles. The active ingredient often only reaches these insufficiently, they survive and continue their journey into the intestine.

Once there, they cause the typical symptoms such as exhaustion, loss of appetite, abdominal pain, bloating or even mucous-bloody diarrhea. Those affected should take the occurrence of such symptoms seriously and contact their doctor for further therapy.

A diet-based parasite cleanse can be administered during or after therapy. Avoiding sugar and carbohydrates literally starves parasites and intestinal fungi. Likewise, an intestinal cleansing with subsequent intestinal sanitation can be carried out after a treatment. Using a stool sample, the composition of the intestinal bacteria is determined in the laboratory and the intestinal flora is built up through the targeted intake of certain bacteria.

In the case of an infestation with skin moles, more precisely the larvae of the hookworm, serious side effects can occur during the course of treatment. Those affected can relieve the itching of the larval ducts under the skin with antihistamines and must contact a doctor immediately if they experience symptoms such as diarrhea, vomiting or feeling unwell.

You can do that yourself

Patients with hookworm disease and skin mole follow the instructions given to them by their doctor. Those affected counter the various symptoms of the disease with adapted measures, whereby prior consultation with the medical care staff is advisable.

First of all, those affected try to resist the unpleasant itching. To support this, patients avoid sweaty activities and irritating cosmetics. If possible, people limit the use of cosmetics on the skin during treatment.

Since those affected also often suffer from nausea and vomiting, a diet is tailored to the symptoms. The food is at best easily digestible and without stomach-irritating foods. In the case of gastrointestinal symptoms, patients allow themselves physical rest and pay more attention to the hygiene of the food consumed.

In some cases, affected patients experience coughing symptoms, and it is helpful to stop, or at least reduce, smoking while treating the disease. Infection with other respiratory diseases should be avoided. Sick people take the drugs prescribed for treatment of hookworm disease and skin mole, following the doctor’s prescriptions for timing and dosage.

Hookworm Disease