- Also called:
- tinea or dermatophytosis
- Related Topics:
- skin disease
- athlete’s foot
- ketoconazole
- Trichophyton
- dermatophyte
- On the Web:
- National Center for Biotechnology Information - Tinea Corporis (Oct. 16, 2026)
ringworm
-
What is ringworm?
Ringworm is a fungal infection of the skin, hair, or nails, marked by ring-shaped, discolored, scaly patches that sometimes blister. Despite its name, ringworm is caused by fungi called dermatophytes, not worms. These fungi thrive on keratin, a protein found in skin, hair, and nails.
Different types of ringworm are named according to the affected body area, such as tinea capitis (scalp), tinea barbae (beard), tinea cruris (groin), tinea manuum (hands), and tinea pedis (feet). Diagnosis involves observation and microscopic examination, and treatment includes topical or oral antifungal medications and, in some instances, limited UV exposure.
2 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
What causes ringworm?
Ringworm is a skin infection caused by a group of fungi called dermatophytes. These fungi thrive on keratin, a protein found in the outer layers of the skin, hair, and nails.
Dermatophytes can be transmitted from person to person or from pets to people, and they can survive on towels, hairbrushes, clothes, and other objects. Ringworm can occur on any part of the body, but common areas include the scalp, groin, and feet.
3 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
What does ringworm look like on the skin?
Ringworm is a fungal infection caused by dermatophytes that feed on keratin on the surface of the skin. These fungi trigger varied skin reactions, from slight scaling to blisters and significant disruption of the keratin layer. Ringworm lesions are typically round or ring-shaped and may be dry and scaly or moist with blisters, varying by body area and fungus type.
Different types of ringworm include:
* Tinea imbricata Lesions consist of concentric rings of overlapping scales.
* Favus Yellow cup-shaped crusts form on the scalp, enlarging into honeycomb-like masses.
* Black dot ringworm Hairs break at the scalp surface, creating a dotted appearance.Ringworm spreads through contact with infected individuals or animals and can survive on objects like towels and clothing.
2 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
How does someone catch ringworm?
Ringworm is a contagious fungal infection of the skin, hair, or nails. It is caused by a specialized group of fungi called dermatophytes, which thrive on the skin's surface and feed on keratin.
Ringworm is also known as tinea, referring to the ring shape of lesions. Transmission occurs through contact. While ringworm of the scalp is highly contagious, the likelihood of contracting other forms depends on individual susceptibility and predisposing factors like excessive perspiration.
3 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
Who is most at risk of getting ringworm?
Ringworm is a fungal infection caused by dermatophytes that feed on keratin on the skin's surface. While anyone can get ringworm, certain groups are more susceptible.
Athletes face a slightly elevated risk due to communal exposure in warm, moist environments like locker rooms. People with hyperhidrosis (excessive sweating) or immune system disorders also have increased vulnerability. Males are more prone to athlete's foot than females, and it's rare before puberty. Contraction of ringworm depends largely on individual susceptibility and predisposing factors.
2 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
How is ringworm treated and prevented?
Ringworm, caused by fungi called dermatophytes, manifests as lesions on the skin, scalp, beard, and nails. Diagnosis involves observation and microscopic examination.
Treatment includes topical or oral antifungal agents, such as ketoconazole, and limited exposure to ultraviolet radiation.
To prevent ringworm, especially of the scalp, avoid sharing personal items like towels and hats. Also, ensure proper hygiene and keep skin dry, as excessive perspiration can be a predisposing factor.
2 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
ringworm, superficial skin lesions caused by a highly specialized group of fungi called dermatophytes that live and multiply on the surface of the skin and feed on keratin, the horny protein constituting the major part of the outermost layer of the skin and of the hair and nails. The fungi produce responses in the skin that vary from slight scaling to blistering and marked disruption of the keratin layer. The lesions are usually round or ring-shaped and can be either dry and scaly or moist and covered with vesicles (blisters), depending on the body area and the type of fungus involved.
Ringworm is also known as tinea, both names referring to the round shape of most of the lesions, similar to the larva of the clothes moth, genus Tinea. In specifying the condition, tinea is usually followed by a modifying term indicating the body area or characteristics of the lesions. Thus, ringworm of the scalp, beard, and nails is also referred to as tinea capitis, tinea barbae or tinea sycosis, and tinea unguium (also called onychomycosis), respectively; ringworm of the body, groin, hands, and feet are referred to as tinea corporis, tinea cruris (also called jock itch), tinea manuum, and tinea pedis, respectively. Tinea pedis is commonly referred to as athlete’s foot, which may be of either the dry or inflammatory type. In the latter type, the infection may lie dormant much of the time and undergo occasional acute exacerbations, with the development of vesicles (blisters) affecting chiefly the skin folds between the toes. The dry type is a chronic process marked by slight redness of the skin and dry scaling that may involve the sole and sides of the foot as well as the toenails, which become thick and brittle.
Other varieties of ringworm are characterized by specific skin lesions. For example, tinea imbricata (Latin: “overlapping like tiles”) is so called because lesions consist of concentric rings of overlapping scales. Tinea imbricata occurs exclusively in Central America, Southeast Asia, India, and Polynesia. Favus, also known as crusted, or honeycomb, ringworm, occurs on the scalp and is characterized by the formation of yellow cup-shaped crusts that enlarge to form honeycomb-like masses. Black dot ringworm, also a ringworm of the scalp, derives its distinctive appearance and name from the breaking of the hairs at the scalp surface. Except for ringworm of the scalp, which tends to be highly contagious, the contraction of ringworm depends to a large extent on individual susceptibility and predisposing factors, such as excessive perspiration.
" height="20" alt="HEW Logo">
Diagnosis of ringworm is made by observation and by microscopic examination. Treatment with topical or oral antifungal agents may be effective. Limited exposure to ultraviolet radiation may also be helpful.