Yaws – Causes, Symptoms & Treatment


Yaws is a non- venereal infectious disease of tropical countries caused by the bacterium Treponema pertenue. The disease, which is contagious via skin contact, belongs to the treponematoses and can be easily treated with antibiotics. If left untreated, the skin disease develops in four stages, beginning with raspberry-like papules and leading to destruction of the bones and joints in the fourth stage over a period of usually more than ten years.

What is yaws?

Yaws is a non-venereal skin disease in tropical countries that is contagious via skin contact and droplet infection and , like venereal and non-venereal syphilis , belongs to the treponematoses. The term yaws is derived from the French framboise for raspberry, because the first stage of the disease is characterized by raspberry-like papules on the skin.

Many other names such as Framboesia tropica or raspberry disease are used synonymously for the disease. The causative agent, the bacterium Treponema pertenue, belongs to the spirochetes. These are thin, spiral-shaped, gram-negative bacteria that can actively move even via internal flagella.

The main area of ​​distribution of yaws are humid tropical countries in Southeast Asia, Africa and Latin America. Typically, the disease progresses – untreated – in four stages, with the third stage, which can last five to ten years, is symptom-free and can give the false impression that the chronic disease has been overcome.


The cause of the chronic skin disease yaws is the bacterium Treponema pertenue, which loves a particularly warm and humid tropical climate. Infection occurs mainly via skin contact and smear infections. In exceptional cases, infections caused by insect bites should also occur.

The close confinement of the rural population, which often occurs in tropical, humid areas, combined with inadequate hygienic conditions, increases the risk of infection. In regions where yaws is endemic, most people become infected as children.

Symptoms, Ailments & Signs

Yaws has an incubation period of three to four weeks and typically presents with one or more “raspberry-like” papules on the skin, preferably on the lower leg. Such papules also develop on the breasts of breastfeeding women. The itchy and weeping papules are painless but cause swelling of the “relevant” lymph nodes. The papules heal – even if left untreated – and new papules develop after a few weeks.

In this second stage, also called the secondary stage, the palms and soles are particularly affected. These newly appeared papules also disappear again after some time and a third, deceptive stage of dormancy follows, which gives five to ten years of freedom from symptoms. Only then does the fourth stage or tertiary stage appear.

The term tertiary stage means that the long symptom-free phase is not counted as a separate phase. During the tertiary stage, changes in bones and joints occur. Tough knots develop in the skin that feel rubbery and the bones and periosteum become inflamed. Skeletal changes and the so-called gangosa, an optically disfiguring remodeling of the nose and throat area, are particularly serious.


An initial diagnosis is made based on the medical history and the conspicuous external signs that accompany the yaws. A morphological distinction between the four different Treponema known to be pathogenic is very laborious and not always reliable.

The symptomatic signs of the disease should be sufficient for a diagnosis that is considered to be reliable, especially since treatment would be possible with less effort overall than a laboratory-based diagnosis. As described above, the course of the disease can be divided into four phases or three stages, with the last phase beginning five to ten years after the original infection.


If left untreated, yaws can lead to serious complications and damage to bones and joints. This damage usually only occurs after a few years and is not immediately visible. In yaws, papules appear on the patient’s skin after about four weeks.

Due to the relatively long incubation period, yaws can only be discovered relatively late by a doctor. The papules continue to spread on the hands and feet and usually disappear again after a short time. At first there are no complications. However, yaws make themselves felt again after about five years.

This results in strong knots on the skin and inflamed bones. This causes severe pain in most patients. Normal everyday life is no longer possible due to yaws. The skeleton changes and those affected are disfigured by malformations on the nose.

Treatment can be by the addition of penicillin and combats yaws with early treatment. If the yaws is only detected in the final stage, healing is usually no longer possible and death occurs. Life expectancy is reduced by yaws.

When should you go to the doctor?

Treatment is always required for yaws. It does not heal on its own and usually worsens symptoms if the condition is not treated. A doctor should be consulted if papules form on the skin. These take on a reddish color and can also be affected by itching. Swelling can also indicate yaws and should be examined.

Although the papules themselves can disappear without treatment, they usually reappear after a few weeks. In the further course, inflammations on the little bones also point to yaws. These are usually noticeable through very severe bone pain, which must be examined by a doctor.

The first diagnosis is made by the dermatologist or by the general practitioner . For further treatment, patients are dependent on taking antibiotics to alleviate the symptoms of the disease. In most cases, the course of the disease is positive and the disease can be well limited.

Treatment & Therapy

As mentioned above, the chronic infectious disease only occurs in warm, humid tropical regions where the rural population often has to live under unsatisfactory hygienic conditions and generally only has very limited financial resources. The standard treatment that has been found effective is a single intramuscular injection of penicillin .

As a result, the disease was greatly reduced within WHO campaigns in the 1950s and 1960s and fell out of focus in the years that followed until it is now on the rise again. A small study by the University of Barcelona, ​​which was carried out in Papua New Guinea in 2013/2014 on over 200 sick children, showed that the effect of a single injection of penicillin did not differ from a single oral dose of the antibiotic azithromycin .

In the “penicillin group” 105 out of 113 patients were cured and in the “azithromycin group” 106 out of 110 patients. This could mean that the disease could be contained or even completely overcome in the future through broad-based, inexpensive treatments with the antibiotic azithromycin.

Outlook & Forecast

Thanks to well-developed and modern medical possibilities, yaws has a favorable prognosis. If the diagnosis is made early and treatment is started quickly, the patient will make a full recovery. The disease trigger can be killed by administering medication.

It is then transported out of the body. The affected person experiences an improvement in health shortly after the start of therapy and is considered to have recovered after a few weeks of the healing process. If no damage to the bone structure has occurred, no consequential damage is to be expected from yaws.

If left untreated, the bacterium can continue to spread unhindered in the organism. The prognosis worsens in these patients. There is a gradual increase in skin changes and swelling. In an advanced stage of the disease, complaints of the bones and joints appear. If the affected person does not seek treatment after a few weeks or months, permanent impairment of the skeletal system sets in.

Inflammation develops, the immune system as a whole is weakened, and the patient’s state of health gradually worsens. Optical changes appear on the face that are irreparable. Existing pain increases in intensity and prevents participation in everyday life. Psychological problems and a drastic drop in well-being are to be expected.


The extremely long course of untreated yaws means that the sufferers are a constant source of infection from which people in the immediate vicinity – especially children – can become infected. A preventive measure that can protect a little against infection is compliance with a minimum hygiene standard.

Smaller and larger injuries to the skin, which the bacteria can use as a portal of entry, are particularly at risk of infection. The best prevention would be if people could be treated with the appropriate antibiotics, penicillin or azithromycin. That would not only heal the sick, but also protect against reinfection because the sources of infection are eliminated.


Aftercare options are severely limited in the case of yaws. Medical treatment of this disease by a doctor is paramount, since self-healing cannot occur. For this reason, early diagnosis with early treatment is very important to prevent further complications and avoid the premature death of the sufferer.

In most cases, yaws are treated with medication, usually antibiotics. The person concerned must ensure that the antibiotics are taken correctly and regularly and follow the doctor’s instructions. Furthermore, no alcohol should be taken with the antibiotics, as the alcohol can weaken the effect of the medication.

Further aftercare measures are not necessary if the disease is cured in time through the use of medication. In the case of complete healing, the life expectancy of the person affected is not reduced. During the treatment, the patient should not exert himself unnecessarily and should take care of his body. A healthy lifestyle with a balanced diet can have a positive effect on the further course of the disease.

You can do that yourself

Yaws is very contagious. If an infection is suspected, it is necessary to consult a doctor immediately. The disease is usually treatable with antibiotics. Education and compliance with hygiene measures are essential and prevent further spread.

There are few things you can do yourself to make living with this condition a little easier. A general healthy diet , exercise in the fresh air and stress management strengthen the immune system and thus the body’s defences, which can then contribute to better health.

Unfortunately, self-healing cannot occur, on the contrary, the symptoms only worsen and the infection spreads further. Due to the long incubation period, it makes sense to get tested as soon as there is a suspicion and to avoid physical contact during this time.

After taking the antibiotic, a quick healing is usually achieved, in which no accompanying measures are necessary. If the disease is advanced, the degree of the secondary disease and the corresponding limitations are important to determine what would make everyday life easier. Since the infectious disease usually spreads in impoverished regions, the offer is very limited.

Website | + posts

Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.