Tinea incognito

Tinea incognito is the name given to tinea when the clinical appearance has been altered by inappropriate treatment, usually a topical steroid cream. Tinea is an infection with a dermatophyte fungus.

The result is that the original infection slowly extends. Often the patient and/or their doctor believe they have a dermatitis, hence the use of a topical steroid cream. The steroid cream dampens down inflammation so the condition feels less irritable. But when the cream is stopped for a few days the itch gets worse, so the steroid cream is promptly used again. The more steroid applied, the more extensive the fungal infection becomes.

Compared with an untreated tinea corporis, tinea incognito:

• Has a less raised margin,
• Is less scaly,
• More pustular,
• More extensive,
• And more irritable.

There may also be secondary changes caused by long term use of a topical steroid such as:

• Atrophy (thin skin, stretch marks (striae) in the skin folds).
• Purpura (bruising) and telangiectasia (broken blood vessels).

Any organism causing tinea corporis may cause tinea incognito,