Yaws is a bacterial skin infection that mostly affects children living in warm, humid tropical areas. It often starts with a painless skin sore and can later cause more skin lesions, swelling, and bone or joint pain. Many people only realize later that their symptoms were connected to yaws. Yaws can last for months or years if it is not treated, but early symptoms of yaws usually improve quickly with antibiotics. Yaws is rarely fatal, but untreated yaws can lead to long-term disability and deformity.
How many people live with Yaws?
Worldwide, about 80,000 to 100,000 people were reported with yaws in a recent year (WHO Global Health Observatory, 2023), and the number varies because many countries count suspected cases based on symptoms rather than cases confirmed by testing. In the United States, the estimate is essentially 0 because yaws is not spread there and no ongoing U.S. cases are reported (CDC Yellow Book, 2024).
Overview
YawsSymptoms
Yaws often starts with a painless skin sore, usually on the legs or feet. Later, more sores can appear, and bones or joints may become painful. Early symptoms of yaws can look like a minor skin infection.
Outlook and prognosis
Yaws usually has an excellent outlook when treated early with antibiotics, often clearing with one dose. Without treatment, it can return and later damage skin, bones, and joints, so follow-up matters.
Causes and risk factors
Yaws is caused by infection with Treponema pallidum pertenue, spread through direct skin contact. Risk is higher in warm, humid areas, especially where overcrowding, poor sanitation, limited clean water, and untreated skin sores make spread easier, mainly in children.
Genetic influences
For Yaws, genetics are not thought to be a main driver. It is mainly linked to infection, though small genetic differences may influence how easily someone gets it or how strongly their immune system responds.
Diagnosis
Doctors diagnose yaws by examining the skin sores and the pattern of rash or bone pain. Blood tests usually confirm it, and a swab from a sore may be tested when the diagnosis of yaws is unclear.
Treatment and drugs
Yaws is treated with antibiotics, most often a single dose of azithromycin by mouth or penicillin as an injection. Skin sores usually start healing within weeks. Close contacts may also need treatment to help stop spread and reinfection.
Symptoms
Yaws often starts with a skin sore that seems minor, then can spread to cause more skin lesions and aching bones if it is not treated. Many living with Yaws notice bumps or crusted patches on the legs and feet first, and later some develop pain that makes walking or play harder. The early symptoms of Yaws can be easy to miss because the first sore is often painless. Symptoms vary from person to person and can change over time.
A small bump or sore often appears where the infection entered the skin, commonly on the legs or feet. It may look red, moist, or crusted, but it is often painless, so it can be easy to ignore.
Weeks to months later, more bumps, sores, or thick patches can appear on the arms, legs, face, or buttocks. In daily routines, this might show up as spots that rub on clothing, crack, or leave lighter or darker marks as they heal.
For many people with Yaws, aching in the bones or joints develops, especially in the legs, fingers, or toes. The pain and swelling can make walking, running, or using the hands less comfortable.
Some may notice puffiness around the fingers, toes, or lower legs from inflammation near the bones. This can make shoes feel tight or make it harder to grip small objects.
How people usually first notice Yaws?
Yaws often first shows up quietly, with a small round sore or bump on the skin, usually on the legs, ankles, buttocks, or arms, in a child living in or recently from a tropical area where the infection occurs. In how yaws is first noticed, families may see that this early spot slowly grows, becomes crusted or moist, and does not heal as expected, while nearby skin may start to thicken or form more bumps. As the infection moves on, some people with yaws also develop bone or joint pain and swelling, which is often the clue that prompts a medical visit.
Types of Yaws
Yaws can look quite different depending on how far the infection has progressed, so the types of yaws are usually described by stage. It often starts with a single skin sore, then may later cause many skin changes and, in some people, deeper damage to bone and tissue if it is not treated. Symptoms don’t always look the same for everyone. The early symptoms of yaws are usually much milder than the late form.
Primary yaws
Primary yaws usually begins with one painless skin growth or ulcer where the bacteria entered the body, often on the legs or feet. This sore may slowly enlarge and can be accompanied by nearby swelling of the lymph nodes.
Secondary yaws
Secondary yaws happens weeks to months later, when several new skin lesions or thickened patches appear on different parts of the body. Many living with yaws may also have bone pain, swelling of fingers or long bones, and trouble walking because the soles become tender and thickened.
Latent yaws
Latent yaws means the infection is still present but there are no obvious symptoms for a period of time. Some may remain in this silent stage, while others later develop more advanced disease.
Tertiary yaws
Tertiary yaws is a late, less common form that can appear years after the earlier stages in people who were not treated. It can damage skin, soft tissue, and bones, sometimes leading to deformity of the nose, legs, or other affected areas.
Can I slow down the onset of symptoms?
No. There is no good evidence that lifestyle changes, diet, exercise, or supplements can meaningfully slow or delay the start of symptoms in yaws. What does help is lowering the chance of infection by avoiding direct skin contact with an active sore and getting checked and treated early with antibiotics if yaws is suspected, because prompt treatment can stop the illness from getting worse but does not guarantee prevention. If you think you or your child may have been exposed, early medical care can make a real difference, even though no step can promise symptoms will never appear.
What genetics can tell you about symptoms
For yaws, genetics usually does not tell us much about which symptoms someone will have, how severe they will be, or when they start. Yaws is an infection caused by a bacterium, so symptoms are driven mainly by catching the infection, how long it goes untreated, and how the immune system responds, rather than by inherited gene changes. Researchers are still learning whether small genetic differences in immune response may affect how the illness looks in some people, but no specific gene pattern is used in routine care to predict symptoms.
Causes and risk factors
Yaws spreads when a type of bacteria passes through direct skin contact with an infected sore. Small cuts or scrapes can make infection easier. Risk is highest for children in warm, humid rural areas. It’s rarely just one factor—it’s the mix that matters. Common risk factors for yaws include crowding, poor sanitation, limited access to clean water or healthcare, and close daily skin contact, while inherited genes do not seem to play a major role.
What are the most common causes or risk factors?
Yaws is caused by infection with a certain type of bacteria that usually spreads through direct skin-to-skin contact with the sore of someone who has it, especially when there are small cuts or scrapes. The biggest risk factors are being a child, living in warm, humid tropical areas, and living in crowded conditions with limited access to clean water, sanitation, and medical care. There are no well-known inherited or genetic risk factors for yaws; it is mainly linked to exposure and living conditions.
Environmental and biological risk factors
Who is at risk for yaws often depends on a mix of body factors and surroundings. Yaws is most common in places where children have frequent close skin contact and where hot, humid conditions make spread easier. Doctors often group risks into internal (biological) and external (environmental).
Yaws most often affects children, especially those roughly 6 to 15 years old. Frequent play and close contact with other children make exposure more likely.
Small cuts, scrapes, insect bites, or other breaks in the skin can make it easier for the bacteria to enter the body. This is one reason yaws can spread during everyday play outdoors.
Direct skin-to-skin contact with an infected sore is the main way yaws spreads. Risk rises when someone lives with or spends a lot of time around people who have untreated yaws.
Yaws is far more common in warm, humid tropical areas. These conditions support ongoing transmission, especially in rural communities.
Genetic risk factors
Yaws is not known to be caused by inherited genes. If you are wondering whether yaws is hereditary, current evidence says it is not considered an inherited disease, and no specific gene changes have been confirmed to raise risk. Researchers have not found a clear genetic pattern in families, so genetic testing is not part of routine yaws care.
No inherited cause: Yaws is not linked to a single changed gene passed from parent to child. It develops because of an infection rather than a known hereditary condition.
Family history: Having relatives who had yaws does not, by itself, mean you inherited a higher genetic risk. Family patterns have not shown the kind of gene-based inheritance seen in true hereditary diseases.
Genetic testing: There is no standard genetic test to predict who will get yaws. Tests for yaws look for signs of the infection itself, not for inherited DNA changes.
Research status: Studies have not identified a reliable gene that clearly makes yaws more likely. At this time, no genetic risk factor is established for yaws.
Lifestyle risk factors
Certain daily habits can increase the chance of catching yaws or make it easier for the infection to spread and last longer. Because yaws passes through direct skin contact with infectious sores, the main lifestyle risk factors involve hygiene, skin care, and how quickly treatment is sought and completed. Understanding how lifestyle affects yaws can help reduce transmission and lower the risk of ongoing infection and relapse.
Infrequent washing of the skin can leave infectious material on the body and make spread between people more likely. Regular cleaning of the skin, especially in children, may help reduce transmission.
Small cuts, scrapes, and untreated sores can make it easier for the bacteria to enter or persist in the skin. Prompt cleaning and covering of skin breaks can lower this risk.
Frequent direct contact with an untreated person's sores raises the chance of infection passing from one person to another. Avoiding contact with active lesions until treatment has started can help limit spread.
Waiting to seek care for suspicious skin sores allows the infection to last longer and increases the chance of passing it to others. Early medical treatment reduces both complications and transmission.
Risk prevention
Yaws risk is lowered mainly by stopping skin-to-skin spread and treating infections early. It often passes between children through contact with moist skin sores during play, especially where people live closely together. Prevention can mean both medical steps, like antibiotics, and lifestyle steps, like keeping skin clean and covered. If you live in or travel to an area where Yaws still occurs, spotting early symptoms of Yaws and getting care quickly can help protect you and others.
The most effective way to prevent Yaws is to diagnose and treat it quickly with the antibiotic your clinician recommends. Early treatment usually stops spread to other people and lowers the chance of later skin, bone, or joint problems.
People living with someone who has Yaws may need evaluation and often treatment too, even if they feel well. This matters because the infection can spread before it is recognized.
Try to avoid direct skin contact with another person's open sores or wet skin lesions in areas where Yaws is present. If a child has suspicious sores, limiting close play contact until treatment starts can reduce spread.
Clean cuts, scrapes, and other breaks in the skin with soap and water, then keep them covered when possible. This can lower the chance that bacteria enter the skin or pass to someone else.
Can you prevent Yaws?
Yaws can often be prevented, but not in every case. The best ways to lower the risk are treating infected people quickly, avoiding direct skin contact with another person's sores, and keeping cuts and scrapes clean and covered, especially in places where yaws is still common. There is no vaccine at this time, so early care and community treatment programs are the main tools for stopping its spread.
Transmission
Yaws spreads mainly through direct skin-to-skin contact with fluid from an active sore, especially if there are small cuts or scrapes on the skin. This means children who play closely together in warm, humid places can pass yaws from one to another, and how yaws spreads is usually linked to repeated close contact rather than brief casual touch.
Yaws is not spread through the air like a cold, and it is not usually passed through food or water. It can be fairly contagious when open sores are present, but once treatment starts, the chance of passing yaws to someone else drops quickly.
When to test your genes
Yaws is an infection, not a genetic condition, so gene testing does not help with early detection or treatment choices. If you have a painless skin ulcer, wart-like growths, or live in or traveled to an endemic area, the right testing is a clinical exam and, when needed, blood tests.
Diagnosis
Yaws is usually diagnosed when a clinician puts together the skin changes, where you live or have traveled, and a few focused tests. The sores can look like other infections, so the diagnosis of yaws often starts with a careful skin exam and questions about close contacts with similar symptoms. It’s natural to worry when symptoms don’t have a clear explanation. In places where yaws is uncommon, doctors may also need to rule out other causes before confirming it.
Doctors look closely at the sores, bumps, or thickened skin and check whether the pattern fits yaws. They also look for signs of later disease, such as painful bone swelling or changes in the hands and feet.
Your clinician will ask about travel or residence in areas where yaws still occurs and whether others nearby have similar lesions. This helps show whether the infection is likely and whether close contacts may also need care.
Blood tests for treponemal infection are commonly used to support the diagnosis. These tests can show exposure to the germ that causes yaws, but they may not always distinguish yaws from syphilis without the full clinical picture.
A second type of blood test may help show whether the infection is currently active and can also be used to follow response after treatment. Doctors usually interpret these results together with symptoms and the exam findings.
How is Yaws diagnosed?
Yaws is usually diagnosed by looking at the skin sores and other signs, asking about symptoms, and finding out whether someone lives in or has traveled to a place where yaws still occurs. To help confirm it, a health care professional may take a swab from a sore or order blood tests, although those blood tests can sometimes also turn positive in another infection called syphilis. Because of that, the diagnosis often comes from the whole picture together, not from just one test alone.
Stages of Yaws
Yaws has recognized stages, and the pattern can stretch over months to years if it is not treated. It usually starts with a skin sore, then may cause more skin changes and, much later in some people, damage to deeper tissues and bone. Early and accurate diagnosis helps you plan ahead with confidence.
Primary stage
Yaws often begins with a single bump or sore, usually on the legs, ankles, feet, or buttocks. This early skin lesion can slowly enlarge and may ooze or form a crust. For many, these are the early symptoms of yaws that first bring them to medical care.
Secondary stage
Weeks to months later, more sores or thickened patches can appear on the skin. Some people also develop bone pain or swelling, especially in the fingers, legs, or around the nose. Walking can become uncomfortable when the feet are affected.
Latent stage
After the visible skin problems settle, yaws can enter a quiet phase with no obvious symptoms. During this stage, the infection is still present in the body even though someone may feel well.
Tertiary stage
Years later, a small number of untreated people develop late yaws with destructive changes in the skin, soft tissues, and bones. This can lead to deformity, chronic pain, and disability, including trouble using the hands or walking normally.
Outlook and prognosis
With timely antibiotic treatment, the outlook for people with yaws is excellent, and most early infections heal completely within weeks to months. Relapses can occur if treatment is delayed or if reinfection happens in endemic communities, so follow-up and treatment of close contacts are important. When yaws is not treated, it can progress over years to destructive skin, soft-tissue, and bone changes that may cause permanent disability and disfigurement, although severe late complications are now much less common where control programs are active. Yaws does not usually affect the brain or heart in the way some other treponemal infections can, and death from yaws itself is rare. Overall mortality is very low, but the disease can still have major long-term consequences for mobility, function, and quality of life if diagnosis and treatment are missed.
Long-term effects
Yaws usually does not cause lasting problems if it is found and treated early. The long-term effects of yaws are mainly seen in people whose infection goes untreated for a long time, sometimes over several years. Long-term effects vary widely, but they can include damage to the skin, bones, and joints, along with changes in walking and appearance.
Repeated or deeper sores can heal with scars, patches of darker or lighter skin, or thicker damaged areas. For many, this can mean visible marks on the legs, arms, or face long after the infection itself has settled.
Yaws can inflame the covering of bones and nearby tissues, leading to ongoing pain and tenderness. Some may find that standing, walking, or climbing stairs stays uncomfortable even after the original skin lesions are gone.
Long-term inflammation around bones can also affect nearby joints, causing stiffness and reduced movement. In daily life, this may show up as trouble bending a knee fully or discomfort when using the hands.
In more advanced untreated yaws, bone damage can change the shape of the legs or other affected areas. Over time, daily routines may become harder because walking can be slower, painful, or less steady.
How is it to live with Yaws?
Living with yaws can start with a sore or skin growth that may not seem dramatic at first, but the pain, itching, and later trouble walking or using affected limbs can make school, work, and daily routines much harder. Because it spreads through direct skin-to-skin contact, many living with yaws may need to avoid close contact until treatment is started, which can strain family life and cause worry or stigma in the community. The good news is that yaws is treatable with antibiotics, and early treatment not only helps the person recover but also protects others around them from catching it.
Treatment and drugs
Yaws is usually treated with antibiotics, and in most people a single dose can clear the infection, especially when it is found early. The main treatment is often azithromycin by mouth, while some people are treated with a penicillin shot if azithromycin is not suitable or not available. Treatment often looks different for each person, because doctors also consider age, pregnancy, allergy history, and whether there are signs of a later-stage infection that may need closer follow-up. Alongside antibiotics, wound care, pain relief, and checking close contacts can help stop yaws from spreading and support healing. If you notice early symptoms of yaws or live in an area where it is more common, getting treated promptly can lower the risk of skin damage and later bone or joint problems.
Can you cure Yaws?
Yes, yaws can usually be cured with antibiotics, often with just one dose if it is found early. Treatment clears the infection and helps stop it from spreading to others, but if yaws has already caused lasting damage to the skin, bones, or joints, those changes may not fully go away.
Non-drug treatment
Yaws can make day-to-day life uncomfortable when skin sores rub on clothing, walking becomes painful, or later bone and joint damage limits movement. Antibiotics are the main treatment for yaws, but supportive care can still help sores heal more comfortably, lower the chance of skin infection, and protect movement and daily function. Beyond prescriptions, supportive therapies can also matter for people with long-standing yaws who have stiffness, deformity, or trouble using an arm or leg.
Gentle washing with clean water and mild soap helps remove dirt and crust from yaws sores. Simple dressings can protect the area, reduce rubbing, and support home care for yaws skin sores.
Keeping the skin clean and dry can lower the risk of added bacterial infection while lesions heal. Clean clothes, bedding, and towels may also help reduce irritation and improve comfort.
Stretching and guided exercises may help if yaws has caused joint stiffness, muscle weakness, or trouble walking. Not every approach works the same way, so therapy is usually tailored to the body part affected and how much movement has been lost.
Splints, braces, supportive footwear, or walking aids can make movement safer for some people living with yaws. These supports may reduce strain on painful joints and help with balance during recovery.
Your genes may have an impact on how drugs work for you
For people with yaws, treatment response is not usually thought to depend much on inherited genetic differences, and genetic testing is not a routine part of care. In everyday practice, whether treatment works is more often linked to things like getting the full treatment, how advanced the infection is, and whether the germ has become less sensitive to the medicine. A person’s body can still react differently to a drug, especially if they have a penicillin allergy or side effects, but this is not a condition where gene-based prescribing is commonly used.
Pharmacological treatments
When yaws causes skin sores, swelling, or bone pain, treatment is usually simple and highly effective. The main treatment for yaws is an antibiotic, most often a single dose of azithromycin by mouth, while a penicillin shot is a trusted backup. Not everyone responds to the same medication in the same way. Early treatment for yaws helps lesions heal and lowers the chance of later bone or tissue damage.
Azithromycin is usually the first-choice medicine for yaws because it can often be given as a single oral dose. Many living with yaws find this easier than an injection, especially during community treatment programs. Doctors may use it for both active infection and close contacts during outbreak control.
Benzathine penicillin G is a single injection that works very well for yaws and has been used for many years. It is often used when azithromycin is not available, cannot be used, or has not worked as expected. People with a history of severe penicillin allergy need a different plan from their healthcare team.
The amount of azithromycin or benzathine penicillin is based mainly on age and body weight, so children and adults may receive different doses. Dosing may be increased or lowered gradually to fit the right amount for the person being treated, although yaws treatment is often given as one dose rather than a long course. Follow-up is still important to make sure sores are healing.
Creams, ointments, or home remedies do not cure yaws because the infection needs an antibiotic that reaches the whole body. If skin lesions remain, come back, or worsen after treatment, clinicians may check for reinfection, another skin condition, or possible antibiotic resistance.
Genetic influences
If several children in one household develop yaws, it can seem as though it runs in the family. It’s natural to ask whether family history plays a role. For yaws, genetics are not thought to be a main driver; the infection is mostly linked to close skin-to-skin contact with someone who has it, along with living conditions and exposure in places where yaws is common. That means family clusters usually happen because relatives share the same environment and contact patterns, not because they inherited a specific gene for yaws. Researchers are still studying whether small differences in immune system genes could affect who gets infected more easily or who develops more noticeable symptoms, but no single gene or inherited pattern has been clearly established. In practice, when doctors think about risk factors for yaws, exposure and community spread matter far more than genetic testing or family history.
Is Yaws genetic?
For Yaws, genetics are not thought to be a main driver. It is mainly linked to infection, though small genetic differences may influence how easily someone gets it or how strongly their immune system responds.
Having a genetic risk is not necessarily a diagnosis
Genetic variants are a usual and common part of human biology. Most of these variants do not have a direct effect on health and are simply part of normal human diversity. For many genes, having a variant connected with a condition suggests a possible link rather than a definite diagnosis, especially when more than one gene and environmental factors are involved. In some situations, though, a single well-characterized variant in a particular gene can be enough to confirm a diagnosis.
Pharmacogenetics—how genetics influence drug effects
For most people living with yaws, treatment is chosen based on the infection and local public health guidance, not on a personal genetic test. In other words, doctors do not routinely use your genes to decide between the main medicines for yaws, which are usually azithromycin or penicillin. Not every difference in response is genetic, but the genes of the bacteria causing yaws can matter: certain changes in the germ can make azithromycin less effective. This is one reason why, if treatment does not work as expected or yaws returns, clinicians may think about reinfection, missed doses, or antibiotic resistance rather than a problem with your own DNA. Penicillin is still an important backup when azithromycin cannot be used or when resistant yaws is suspected. So when people ask about genetic testing for yaws treatment, the most useful genetic information is usually about the bacteria, not the person receiving the medicine.
Interactions with other conditions
People with yaws may also be checked for other infections that can cause similar skin sores or bone and joint symptoms, because these can be easy to mix up at first. In places where yaws is common, doctors often think carefully about syphilis, since the germs are closely related and blood tests can sometimes look similar, even though the infections spread in different ways. Another important aspect is how it may link with other diseases. If someone is also living with a condition that weakens wound healing or raises the chance of skin infection, such as diabetes or poor nutrition, yaws sores may take longer to settle and may be more likely to become secondarily infected with bacteria. In everyday life, this can mean a child’s leg sore seems slow to improve, or walking becomes more painful because swelling and skin breakdown are happening at the same time. Because the early symptoms of yaws can overlap with other tropical skin diseases, getting the right diagnosis matters so treatment is aimed at the true cause and any coexisting illness is not missed.
How genes can cause diseases
Humans have more than 20,000 genes, each carrying out one or a few specific functions in the body. One gene instructs the body to digest lactose from milk, another tells the body how to build strong bones and another prevents the body's cells from beginning to multiply uncontrollably and developing into cancer. As all of these genes combined are the building instructions for our body, a defect in one of these genes can have severe health consequences.
Through decades of genetic research, we know the genetic code of any healthy/functional human gene. We have also identified that in certain positions on a gene, some individuals may have a different genetic letter from the one you have. We call these hotspots "Genetic Variations" or "Variants" in short. In many cases, studies have been able to show that having the genetic letter "G" in the position makes you healthy, but having the letter "A" in the same position disrupts the gene function and causes a disease. Genopedia allows you to view these variants in genes and summarizes all that we know from scientific research, which genetic letters (Genotype) have good or bad consequences on your health or on your traits.
What other conditions can cause similar symptoms to Yaws?
Yaws can look a lot like syphilis, a different infection caused by a close relative of the same germ, and it can also be mistaken for common bacterial skin infections that cause sores, crusts, or swollen lumps. In areas where yaws is more common, doctors may also consider tropical skin ulcers and other long-lasting skin infections that can leave open sores. If there is bone or joint pain, they may also need to rule out injuries or other infections that can cause swelling and aching.
History
Long before there were lab tests, families saw the effects of yaws in everyday life. Children might develop sore, raised skin spots that made walking painful, and over time some were left with lasting changes in the skin, bones, or joints. In many tropical regions, these patterns became familiar even if the cause was not yet understood.
Across cultures and time periods, yaws was observed in warm, humid parts of Africa, Asia, the Pacific, and the Americas. Early medical descriptions appeared centuries ago, often grouping it with other illnesses that caused skin sores because doctors had few tools to tell them apart. As medical science improved in the late 1800s and early 1900s, researchers began to separate yaws from related infections and recognized that it spread mainly through close skin-to-skin contact, especially among children.
By the mid-20th century, yaws had become a major public health focus. Large treatment campaigns using antibiotics reached many communities and sharply reduced cases in several countries. For a time, it seemed possible that the disease might disappear, but when surveillance and treatment programs slowed, yaws returned in some areas where poverty, crowding, and limited access to healthcare made spread easier.
More recent work has brought clearer testing, better mapping of where cases still occur, and renewed international efforts to eliminate yaws. This has also improved understanding of the early symptoms of yaws, helping health workers identify and treat people sooner. The history of yaws is a reminder that progress can be real and lasting, but only if diagnosis, treatment, and community health programs continue over time.