Ringworm
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Direct answer
Ringworm is one of the most common fungal diseases of humans, caused by species of the genera Trichophyton, Microsporum and Epidermophyton. These dermatophytes grow in the keratinised layers of the skin, nails and scalp, producing dry, scaly, ring-shaped lesions with intense itching. Infection is acquired from soil or by using towels, clothes or combs of infected individuals, and the heat and moisture of skin folds favour fungal growth.
What you must remember
- Causative organisms: the fungi Trichophyton, Microsporum and Epidermophyton — the three dermatophyte genera named in NCERT.
- Sites: the skin, nails and scalp; the groins and the skin between the toes (athlete's foot) are typical warm, moist spots.
- Symptoms: dry, scaly lesions appearing as ring-like patches on the body, accompanied by intense itching.
- Transmission: direct acquisition from soil, or through shared articles such as towels, clothes and combs contaminated with fungal spores.
- Predisposing factors: heat and moisture, which accelerate dermatophyte growth — explaining the predilection for skin folds and the flare-up in humid weather.
- Hygiene rule: personal articles should never be shared, and affected skin should be kept dry and clean.
- Grouping: ringworm is the classic fungal entry in the NCERT pathogen table, set apart from the bacterial, viral, protozoan and helminthic diseases.
Common confusion
Despite its name, ringworm is a fungal infection and has nothing to do with worms — the ring is the expanding rim of scaly skin. Students frequently misfile it with helminthic diseases because of the word "worm". Its mode of spread also differs from most table entries: it comes from soil and fomites such as combs and towels rather than from droplets or vectors.
Exam-focused takeaway
NEET-UG asks the three fungal genera in match-the-following formats and stresses ringworm's sites — skin, nails, scalp, groin and between the toes — with the dry, scaly, itchy lesion description. Statement items test acquisition from soil and shared articles and the role of heat and moisture in aggravating the lesions. Expect one-liner MCQs on the fact that ringworm is mycotic, not helminthic.
Frequently asked questions
Which fungi cause ringworm?
Species of Trichophyton, Microsporum and Epidermophyton, the dermatophyte fungi of human skin.
Is ringworm caused by a worm?
No — it is a fungal infection; the name refers only to the ring-shaped appearance of the scaly lesions.
Which body parts are affected?
The skin, nails and scalp, with common involvement of the groin and the spaces between the toes known as athlete's foot.
How does ringworm spread?
From soil directly, or through shared towels, clothes and combs carrying fungal spores from an infected person.
Why do ringworm lesions worsen in heat and moisture?
Because warmth and humidity favour rapid growth of the dermatophyte fungi, which is why skin folds are most often affected.