How Common Is Ringworm and Who Gets It Most?

Ringworm is one of the most common infections on the planet. A cross-sectional analysis using data from the Global Burden of Disease Study 2017 estimated that roughly 750 million people worldwide were living with fungal skin diseases at any given time, and dermatophyte infections (the group that includes all forms of ringworm) make up the bulk of that number.¹ Despite its name, ringworm has nothing to do with worms. It is a fungal infection of the skin, scalp, or nails caused by organisms that feed on keratin, the protein in your outer skin layer and hair. Who gets it most depends on age, geography, living conditions, and what you do with your days.

How Many People Are Affected Globally

That 750-million figure covers all fungal skin diseases, but dermatophytosis, the clinical name for ringworm, is the dominant contributor. The burden is not evenly distributed. Sub-Saharan Africa carries the highest disability-adjusted life-year (DALY) rates from fungal skin disease, roughly 89 per 100,000 for males and 78 per 100,000 for females. By contrast, high-income regions such as western Europe, North America, and Australasia sit at roughly 30 to 33 per 100,000.¹ Those numbers reflect not just how many people catch ringworm but how much suffering it causes, accounting for itching, scarring, stigma, and lost school or work days.

The gap between regions is driven largely by climate, crowding, access to healthcare, and the availability of antifungal treatments. Tropical and subtropical climates favor fungal growth, and limited access to clean water or medical care means infections linger longer and spread more easily. But ringworm is by no means a developing-world-only problem. Athlete’s foot alone has an estimated global prevalence of around 10%, and it shows up in every country where people wear enclosed shoes and share locker rooms.²

Children Are the Most Affected Age Group

The GBD data showed that the disease burden peaks sharply between the ages of one and five, then stays elevated throughout childhood before tapering in adulthood.¹ The main culprit in young children is tinea capitis, ringworm of the scalp. This form is especially common in school-age kids in sub-Saharan Africa and parts of South Asia, but it appears everywhere.

A study of schoolchildren in Gondar, Ethiopia, found a prevalence of about 29% for scalp ringworm. Children between five and eight years old were nearly four times as likely to be affected as older students. Having a family member with a similar infection raised the odds dramatically, about eightfold, and contact with animals roughly doubled the risk.³ In Mauritania, a school-based survey found that over half the children screened carried scalp dermatophytes on fungal culture. The strongest predictor was sleeping arrangements: prevalence jumped from about 1% in children who slept alone to about 76% in children who shared a bed with multiple others.⁴

Why children? Part of the answer is biological. The scalp environment in prepubescent children has less of the fatty acids produced after puberty that help inhibit fungal growth. Part of it is behavioral: kids share hats, combs, and pillows, and they play in close physical contact. And part of it is environmental, since schools and daycares put large groups of children in tight quarters day after day.

Athletes and Contact-Sport Transmission

If children are the most affected age group overall, athletes in contact sports are the most concentrated risk group among older adolescents and adults. Wrestlers, in particular, deal with a specific form known as tinea gladiatorum, which spreads through direct skin-to-skin contact during matches and training. Outbreaks are typically caused by the dermatophyte Trichophyton tonsurans, the same species responsible for most scalp ringworm in children.⁵

A two-year analysis of wrestling clubs in Tehran found that T. tonsurans accounted for more than 90% of all ringworm isolates from wrestlers with body ringworm. Nearly three-quarters of affected wrestlers were between ten and twenty years old.⁶ The infection tends to appear on the head, neck, and arms, the areas that make the most contact during grappling. In competitive wrestling, outbreaks can sideline entire teams, and athletic governing bodies in many countries now require skin checks before matches.

An interesting wrinkle: the mats themselves may not deserve the blame they usually get. A study that swabbed wrestling mats at eight schools failed to grow any dermatophytes from the surfaces, even under ideal laboratory conditions. The researchers concluded that mats are unlikely to be a meaningful source of ringworm infections in wrestlers, and that direct person-to-person contact is the primary route.⁷ That finding runs counter to what most coaches and parents assume, but it lines up with the microbiology: dermatophyte spores survive well on shed skin cells and hair fragments, less well on bare rubber or vinyl.

Beyond wrestling, sporting activity in general raises the risk of foot fungus. The large Achilles survey found that more than half of patients visiting a general practitioner had signs of foot disease, and roughly two-thirds of those showed evidence of a superficial fungal infection. A significant age-dependent link between sporting activity and foot infections was noted, especially among children.⁸ Shared showers, damp socks, and warm shoes create exactly the conditions fungi thrive in.

Pets and Other Animal Sources

You do not need to be an athlete or a schoolchild to pick up ringworm. One of the most common routes for household infections is a new kitten or puppy. The dermatophyte species that live on animals, particularly Microsporum canis in cats, are highly contagious to humans.⁹ Young cats and cats living in shelters or multi-cat environments are the most frequent carriers, and they can shed spores even when they look perfectly healthy. If you adopt a kitten and a week later notice a round, scaly patch on your forearm, the connection is usually straightforward.

Other animals carry ringworm too. Cattle, rabbits, guinea pigs, and hedgehogs each have their own common dermatophyte species, and people who handle these animals regularly, whether as farmers, veterinary workers, or pet owners, face higher exposure. The fungi are categorized by their preferred host: zoophilic species come from animals, anthropophilic species prefer humans, and geophilic species live in soil. Zoophilic infections tend to produce more inflammation in humans than the species adapted to us, which means the lesions from a cat or cow are often angrier-looking and more uncomfortable than a ringworm patch caught from another person.¹⁰

Overcrowding, Poverty, and Housing

Across dozens of studies in different countries, the same pattern appears: higher population density means more ringworm. Globally, dermatophytosis rates are consistently higher in overcrowded homes, schools, and institutional settings.¹¹ In a study of primary-school children in rural Gombe, Nigeria, low socioeconomic status, overcrowding in mud houses, and poor hygiene practices were all identified as independent drivers of tinea capitis.¹²

The mechanism is simple: dermatophytes spread through shed skin and hair fragments, so the more people sharing beds, towels, combs, and floor space, the more chances the fungus has to jump from person to person. The Mauritanian school study made this vivid by showing a near-linear relationship between crowding at bedtime and infection rates.⁴ Poverty also limits access to antifungal medications, meaning infections persist longer and spread to more contacts before they are treated.

People With Weakened Immune Systems

For most healthy people, ringworm is annoying but superficial. It stays in the outer layers of dead skin and responds to a few weeks of antifungal cream or, for scalp and nail infections, a course of oral medication. But in people with compromised immune systems, the picture changes dramatically. Dermatophytes can invade deeper tissues, causing conditions such as Majocchi’s granuloma, where the fungus penetrates into hair follicles and the surrounding dermis, or deep dermatophytosis, where it spreads to subcutaneous tissue or even internal organs.¹³

Severe forms have been documented in organ transplant recipients on immunosuppressive drugs, people with HIV, patients on long-term corticosteroids for autoimmune conditions, and individuals with rare inherited immune deficiencies. These cases are uncommon, but they highlight the fact that dermatophytes are held in check by a functioning immune system. When that defense is weakened, a common fungus can become a serious medical problem.

The Hidden Role of Asymptomatic Carriers

One of the reasons ringworm keeps circulating so stubbornly, especially in families and schools, is that many people carry the fungus without any visible symptoms. A study of households with a child diagnosed with tinea capitis found that about 16% of household contacts were asymptomatic carriers at the initial visit. In nearly a third of families, at least one other person was silently harboring the fungus.¹⁴ Over six months of follow-up, the carrier state gradually cleared in most people, but some remained positive for months, and one carrier eventually developed a full-blown scalp infection.

These silent carriers act as persistent reservoirs. When a child finishes treatment and the infection clears, a carrier sibling or parent can reintroduce the fungus, leading to the frustrating cycle of reinfection that dermatologists see regularly. Evidence suggests that asymptomatic carriage plays a significant role in fueling outbreaks and maintaining endemic transmission in communities.¹⁵ Whether and how aggressively to treat carriers remains debated, but identifying them through scalp cultures in the household is an important step when a child keeps getting reinfected.

Barber Shops and Shared Grooming Tools

An underappreciated transmission route involves barbershops and hair salons. A retrospective cohort study traced an infection chain of scalp and beard ringworm caused by Trichophyton tonsurans back to contaminated hairdressing tools. All samples from affected patients grew the same species, and the clinical histories pointed clearly to shared clippers and razors as the source.¹⁶

Dermatophyte spores can persist on brushes, towels, cushions, and electric razors for extended periods. A multicenter case series describing outbreaks linked to shave haircuts found that identifying contacts of the index case and testing them for asymptomatic carriage was essential to breaking the chain. The authors stressed that instruments touching the skin should be either disposable or sterilized in an autoclave between clients.¹⁷ Alcohol wipes and simple disinfectant sprays may not reliably kill dermatophyte spores, so if your barber is using unsterilized blades on a line of customers, the risk is real. This route is particularly relevant for men and boys getting close-cropped or faded cuts where the blade contacts the scalp directly.

How Climate and Geography Shape the Fungal Landscape

Ringworm thrives in warmth and moisture, so tropical and subtropical regions have always carried a heavier burden. But that geography may be shifting. Climate change, driven by greenhouse gas emissions, is altering temperature and precipitation patterns in ways that affect fungal growth and distribution. Researchers have noted that these changes may expand the geographic range of pathogenic fungi, potentially exposing populations in temperate regions to species and strains they have not encountered before.¹⁸

The species mix has already shifted considerably over the past century. A hundred years ago, the dominant ringworm pathogens were Epidermophyton floccosum, Microsporum audouinii, and Trichophyton schoenleinii. Since the mid-twentieth century, those species declined dramatically and are now mostly limited to some less-developed countries. Meanwhile, Trichophyton rubrum, T. interdigitale, T. tonsurans, and Microsporum canis have risen to become the globally dominant species.¹⁹ That shift reflects changes in urbanization, hygiene practices, migration, and the global movement of pets and livestock. Dermatophytes evolve alongside human societies, and the species you are most likely to encounter today depend on where you live, what animals you keep, and who you come into contact with.

Drug-Resistant Ringworm Is a Growing Concern

For decades, ringworm was considered easy to treat. A tube of over-the-counter antifungal cream handled most body and groin infections, and oral terbinafine or griseofulvin dealt with scalp and nail cases. That comfortable assumption is being challenged by the emergence of Trichophyton indotineae, a species first identified in India that has since been detected across Europe, North America, and other regions. T. indotineae shows reduced susceptibility to multiple antifungal drugs, including terbinafine and fluconazole, which are two of the most commonly used treatments.²⁰

Clinicians in South Asia were among the first to notice that ringworm infections were becoming harder to clear, requiring longer courses of treatment or combination therapy. The strain has since been isolated in Italy, Germany, France, the United States, and elsewhere, raising concern that resistant ringworm could become a global problem. For the average person, this means that a ringworm patch that does not respond to standard over-the-counter cream within a few weeks deserves a visit to a healthcare provider, who may need to send a sample for fungal culture and susceptibility testing rather than simply prescribing the usual medications.

Sex Differences and Age Patterns in Adults

In adults, men tend to get ringworm more often than women. Athlete’s foot is a clear example: males are more commonly infected than females.² The reasons are likely a combination of occupational exposures, footwear choices, and higher participation rates in contact sports and manual labor. Jock itch (tinea cruris) also skews male, partly because the anatomy of the groin creates a warmer, more occluded environment in men.

The GBD data showed that fungal skin disease DALYs were slightly higher in males than females across all ages, though the gap was modest: about 56 per 100,000 for men versus 53 per 100,000 for women globally.¹ This is not a dramatic difference, and in some settings the pattern reverses. In tropical regions, women who spend extended time in wet agricultural environments or who wash clothes by hand in streams may be equally or more susceptible to certain forms. The sex difference, in other words, is more about lifestyle exposure than about biology.

What You Can Actually Do About It

If you are trying to reduce your own risk or protect your family, the practical steps follow directly from the transmission patterns. Ringworm spreads through direct skin contact and through contaminated objects like combs, towels, and bedding. Keeping personal items personal is the single most effective preventive measure. For families dealing with recurrent scalp ringworm in children, screening household members for asymptomatic carriage is worth discussing with a dermatologist, since an undetected carrier may be reintroducing the fungus.¹⁴

For athletes, skin checks before training sessions and prompt treatment of any suspicious lesion are more effective than obsessive mat-scrubbing, given the evidence that mats are not a major source.⁷ For pet owners, a new puppy or kitten with patchy fur or crusty skin should see a vet before cuddling on the couch. And for anyone getting a close haircut, it is reasonable to watch whether your barber sterilizes blades between clients. The fungus itself is common and nearly impossible to avoid entirely, but the people who get it most are the ones whose daily circumstances put them in repeated, close contact with other infected skin, whether that skin belongs to a classmate, a teammate, a family member, or a cat.

1
PubMed Central. The global, regional, and national burden of fungal skin diseases in 195 countries and territories: A cross-sectional analysis from the Global Burden of Disease Study 2017
2
Archives of Pediatrics & Adolescent Medicine. Athlete’s foot epidemiology and demographics
3
PubMed Central. Tinea capitis and its associated factors among school children in Gondar town northwest, Ethiopia
4
PubMed Central. Epidemiology of scalp ringworms and superficial fungal infections in schools in Mauritania
5
PubMed. Tinea gladiatorum: wrestling’s emerging foe
6
PubMed Central. OUTBREAK OF TINEA GLADIATORUM IN WRESTLERS IN TEHRAN (IRAN)
7
PubMed Central. Wrestling mats: are they a source of ringworm infections?
8
Journal of the European Academy of Dermatology and Venereology. Prevalence of superficial fungal infections among sports‐active individuals: results from the Achilles survey, a review of the literature
9
Journal of Small Animal Practice. Ringworm in dogs and cats
10
ScienceDirect. Skin, soft tissue, bone and joint infections Superficial fungal infections
11
PubMed Central. Social determinants of health as drivers of fungal disease
12
UMYU Journal of Microbiology Research. Prevalence of Tinea capitis among Primary School Children of a Rural Community in Gombe, Nigeria, and Associated Predisposing Factors
13
PubMed Central. Severe Dermatophytosis and Acquired or Innate Immunodeficiency: A Review
14
Archives of Pediatrics & Adolescent Medicine. Asymptomatic Dermatophyte Carriers in the Households of Children With Tinea Capitis
15
PubMed. Tinea capitis asymptomatic carriers: what is the evidence behind treatment?
16
PubMed. Tinea capitis et barbae caused by Trichophyton tonsurans: A retrospective cohort study of an infection chain after shavings in barber shops
17
Actas Dermo-Sifiliográficas. Outbreak of Dermatophyte Infections on the Head and Neck Related to Shave Haircuts: Description of a Multicenter Case Series
18
PubMed Central. The impact of climate change on the epidemiology of fungal infections: implications for diagnosis, treatment, and public health strategies
19
PubMed. The Changing Face of Dermatophytic Infections Worldwide
20
Mycoses. Clinical Characteristics and Genomic Analysis of a Trichophyton indotineae Strain Resistant to Terbinafine and Fluconazole Isolated in Italy