Epidermophyton floccosum is a species of dermatophytes which are a
distinct group of fungi that infect the skin, hair and nails of humans and
animals, producing a variety of infections commonly known as "ringworm."
Dermatophytes (ringworm fungi) invade only the horny, outermost layer of the
skin, and the inflammation they cause is a result of metabolic products of the
fungus or delayed hypersensitivity.
Epidermophyton floccosum is characterized by the production of
smooth-walled, two- to four-celled thick, egg-shaped asexual spores
(macroconidia) in clusters of two or three which are borne on hyphae (a mass of
branching filaments). The hyphae grow rapidly to produce circular
lesions. The macroconidia may have one or more septa (partitions). No small
conidia (microconidia) are produced. The color of the colony is
In general, fungi that can be transmitted to humans by animals cause a more
severe inflammation than those spread from person to person. Ringworm is
contagious. Infections are acquired from active ringworm lesions on humans
(anthropophilic), animals (zoophilic), or from soil (geophilic).
Clinically, ringworm is referred to as tinea and the locations involved are
usually the surface of the body (tinea corporis), the scalp (tinea capitis), the
foot (tinea pedis, or athlete's foot), and the nails (tinea unguium, or
Tinea cruris (tinea inguinalis) occurs on smooth skin in those parts which
are likely to be moist, most frequently the inner surfaces of the thighs,
armpits, the folds of the buttocks, and under the breasts. It occurs more
frequently in warm climates.
Epidermophyton floccosum is one of the fungal species that cause tinea
pedis (athlete's foot) characterized by soggy, scaling skin between the toes and
recurrent outbreaks of blistering.
Epidermophyton floccosum is also often isolated in tinea corporis
(ringworm). Skin fissures can lead to secondary bacterial infections, with
consequent lymph node inflammation.Epidermophyton floccosum
has been linked to reticulum cell carcinoma, or histiocytic malignant
References: 1. Koneman's color atlas and textbook
of diagnostic microbiology By Washington C. Winn, Elmer W. Koneman
2. Henrici's Molds, Yeasts and Actinomycetes by Charles E. Skinner
3. Lippincott's Illustrated Reviews: Microbiology By Richard A. Harvey, Pamela C. Champe, Bruce D. Fisher
4. Clinical Dermatology By Richard P. J. B. Weller, J. A. A. Hunter,
Mark V. Dahl; 5. District Laboratory Practice in Tropical Countries, Part 2 By