Favus
| Favus | |
|---|---|
| Other names | Tinea favosa[1] |
 | |
| An infant with favus, in Kharah, Akhnoor District, Jammu & Kashmir, India. | |
| Specialty | Infectious diseases  |
Favus (Latin for "
The word favid is more used than French word favus, which is close to the Latin etymology.[citation needed]
Presentation
The uncomplicated appearance is that of a number of yellowish, circular, cup-shaped crusts (scutulum or shield) grouped in patches like a honeycomb, each crust about the size of a split pea, with a bundle of hair projecting in the center. These increase in size and become crusted over, so that the characteristic lesion can only be seen round the edge of the scab. A mousy odour is often present. Growth continues to take place for several months, when scab and scutulum go away, leaving a shining bare patch destitute of hair. The disease is essentially chronic, lasting from ten to twenty years. It is caused by the growth of a fungus, and pathologically is the reaction of the tissues to the growth.[3]
The fungus was named after a microscopic structure termed "achorion" (a term not used in modern science), seen in scrapings of infected skin, which consists of slender,
During initial infection, the fungal spores would appear to enter through the unbroken cutaneous surface, and to germinate mostly in and around the hair follicle and sometimes in the shaft of the hair.
Species
Favus is the first human
In 1892, two additional "species" of the fungus were described by Paul Gerson Unna: the Favus griseus, giving rise to greyish-yellow scutula; and the Favus sulphureus celerior, causing sulfur-yellow scutula of a rapid growth.[3] This was in the days before scientists learned to rigorously distinguish microorganism-identities from disease-identities, and these antique, ambiguous disease-based names no longer have status either in mycology or in dermatology today.
Similar looking infections, sometimes diagnosed as favid but more often as atypical inflammatory tinea, may be caused by more common dermatophyte infections, in particular Microsporum gypseum, the most common soil-borne dermatophyte, and Trichophyton quinckeanum. The latter was previously called Trichophyton mentagrophytes var. quinckeanum, the agent of mouse favus infection.
Treatment
Up until the advent of modern therapies, favus was widespread worldwide; prior to Schönlein's recognition of it as a fungal disease, it was frequently confused with
References
- ^ "Favus: Background, Pathophysiology, Epidemiology". 2017-07-17.
- ^ "favus" at Dorland's Medical Dictionary
- ^ a b c d Chisholm 1911.
- This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). "Favus". Encyclopædia Britannica. Vol. 10 (11th ed.). Cambridge University Press. p. 215.
- Kane, J., R.C. Summerbell, L. Sigler, S. Krajden, G. Land. 1997. Laboratory Handbook of Dermatophytes: A clinical guide and laboratory manual of dermatophytes and other filamentous fungi from skin, hair and nails. Star Publishers, Belmont, CA.
- Gräser Y, Kuijpers AF, Presber W, De Hoog GS (October 1999). "Molecular taxonomy of Trichophyton mentagrophytes and T. tonsurans". Med. Mycol. 37 (5): 315–30. PMID 10520156.
