Dermatophytosis is a papulosquamous eruption (tinea corporis, tinea manuum, tinea cruris, and tinea pedis). Workers who handle farm and pet animals are at risk for fungal skin infections (veterinarian, zookeeper, laboratory animal worker, farmer, pet shop worker).
CASES/YEAR
870,000 (US); 17,400,000 (Global)
AGENT TYPE
Fungi (Dermatophytes)
OTHER NAMES
Zoophilic dermatophyte infections (Trichophyton verrucosum or Microsporum canis);
INCUBATION
4-14 days (scalp and body)
INITIAL SYMPTOMS
"The archetypal lesion of dermatophytosis is an annular scaling patch with a raised margin showing a variable degree of inflammation; the center is usually less inflamed than the edge." [PPID, p. 3203]
PRECAUTIONS
Standard; "Rarely, outbreaks have occurred in healthcare settings, (e.g., NICU, rehabilitation hospital. Use Contact Precautions for outbreak." [CDC 2007 Guideline for Isolation Precautions]
COMMENTS
Dermatophytoses are papulosquamous eruptions (tinea corporis, tinea manuum, tinea cruris, and tinea pedis). [Cecil, p. 2620] Workers who handle farm and pet animals are at risk for fungal skin infections (veterinarian, zookeeper, laboratory animal worker, farmer, pet shop worker). [ABX Guide: Tinea corporis] Dermatophytes are fungi that cause superficial skin, hair, and nail infections. They are of three types: zoophilic, anthropophilic, and geophilic based on their source from animals, humans, or soil, respectively. The most common zoophilic dermatophytes in temperate countries are Trichophyton verrucosum, the cause of cattle ringworm, and Microsporum canis, which infects dogs and cats. Also associated with dermatophytoses are pigs, rodents, horses, hedgehogs, bank voles, and monkeys. Most human dermatophytoses are anthropophilic. [PPID, p. 3201-2] Tinea infections are increased in severity, but not in frequency, in HIV infected patients. [ID, p. 1018] See "Tinea capitis," "Tinea corporis, cruris, and pedis," "Tinea versicolor," and "Onychomycosis."
DIAGNOSTIC
KOH prep; Culture
SIGNS & SYMPTOMS
-
S cellulitis or rash, circinate
-
S papules or plaques
-
S pustule
-
S rash on palms
-
S skin blister or vesicles
ENTRY
Skin or Mucous Membranes (Includes Conjunctiva)
SOURCE
Soil or Dust (Ingesting or Inhaling)
RESERVOIR
Cattle, Goats and Sheep, Cats, Dogs, Horses, Monkeys, Rodents, Swine, Human, Wild Animals
RISK FACTORS
- AIDS patients
- Handle domestic animals
- Touch infected farm animals
REFERENCES FOR CASES/YEAR
1. (US) Using incidence of 2.9 cases/1000/year in an Australian study: 2900/million X 300 = 870,000; [PMID 14616492]
2. (Global) Using incidence of 2.9 cases/1000/year in an Australian study: 2900/million X 6 billion = 17.4 million; [PMID 14616492]