A genus of fungi, causes tinea

Tinea is a term given to dermatophyte fungal infections. Three main types of infection are described depending on what part of the body is infected

• tinea capitis - scalp
• tinea corporis - trunk, legs or arms
• tinea pedis - feet

Tinea capitis (scalp ringworm)

• most common cause is Trichophyton tonsurans in the UK and the USA
• may also be caused by Microsporum canis acquired from cats or dogs

PC:

• a cause of scarring alopecia mainly seen in children
• if untreated a raised, pustular, spongy/boggy mass called a kerion may form

Ix:

• Woods lamp
  • lesions due to Microsporum canis green fluorescence under Wood's lamp
  • lesions due to Trichophyton species do not readily fluoresce under Wood's lamp
• the most useful investigation is scalp scrapings

Tx:

• oral antifungals:
  • terbinafine for Trichophyton tonsurans infections
  • griseofulvin for Microsporum infections.
• Topical ketoconazole shampoo should be given for the first two weeks to reduce transmission

Tinea corporis (ringworm)