Id reactions

Secondary reactions to fungi (trichophytes, epidermophytid, microsporid) in hyperergic immune state.

In the case of dermatophyte infection, an antigen resorption and finally an antigen-antibody reaction occur in a hyperergic immune situation. From an immunological point of view, this is a type IV reaction. The Id reaction usually occurs far from the focus.

Dyshidrosiform, nodular or multiforme erythema, usually on the extremities.

Lichen trichophyticus is a special form: This is a symmetric, disseminated seeding of follicular papules localised to the trunk.

Anamnesis

Clinical

Mycological diagnosis

Immune testing is not recommended

Very good if the causative mycosis is treated effectively.

Treatment of the underlying mycosis.

1. Atzori L, Pau M, Aste M. Erythema multiforme ID reaction in atypical dermatophytosis: a case report. J Eur Acad Dermatol Venereol. 2003 Nov;17(6):699-701. 
2. Sorey W. Diagnosis: Dermatophytid reaction (Id reaction). Commentary. Clin Pediatr (Phila). 2009 Apr;48(3):335. 
3. Iglesias ME, España A, Idoate MA, Quintanilla E. Generalized skin reaction following tinea pedis (dermatophytids). J Dermatol. 1994 Jan;21(1):31-4. 
4. Mayser P. Dermatophyte : Current situation. Hautarzt. 2017 Apr;68(4):316-323.