Dermatol. praxi. 2026;20(1):36-38 | DOI: 10.36290/der.2026.001
Id reaction following impetiginized contact dermatitis
- Pediatrická klinika, FN Brno a LF MU v Brně
An id reaction (autosensitization dermatitis) is a generalized, immunologically mediated skin response that develops secondarily as a result of a distant primary focus. It typically occurs in patients with eczema or fungal and bacterial skin infections, yet in clinical practice it is often overlooked or misdiagnosed. Successful resolution depends on adequate treatment of the primary lesion together with symptomatic management of the id reaction. We present the case of a 12-year-old patient with impetiginized contact dermatitis of the left knee following trauma, complicated by the development of an id reaction on the trunk, neck and axillary regions. The condition was accompanied by peripheral eosinophilia. Owing to the extent of the skin involvement, a combination of topical and systemic therapy was initiated, leading to regression of both the primary and secondary skin lesions. This case highlights the importance of quick recognition of id reactions, appropriate microbiological assessment and targeted treatment of the primary focus. It also emphasizes the risk of misdiagnosis as a drug-induced exanthema.
Keywords: id reaction, autosensitization dermatitis, contact dermatitis, impetiginization, eosinophilia.
Accepted: December 15, 2025; Published: April 8, 2026 Show citation
References
- Eichenfield LF, Frieden IJ, Esterly NB. Autosensitization dermatitis (Id reaction). In: Hurwitz Clinical Pediatric Dermatology. 6th ed. Philadelphia: Elsevier; 2021;(73):468-471.
- Bertoli MJ, Schwartz RA, Janniger CK. Autoeczematization: A Strange Id Reaction of the Skin. Cutis. 2021 Sep;108(3):163-166. doi:10.12788/cutis.0342.
Go to original source... 
Go to PubMed... - Ferree SD, Yang C, Kourosh AS. Autosensitization dermatitis: A case of rosacea-like id reaction. JAAD Case Rep. 2019 Apr 20;5(5):410-412. doi:10.1016/j.jdcr.2019.02.029. Go to original source... Go to PubMed...
- Treat JR. Tinea capitis: Clinical features and diagnosis. In: UpToDate [Internet]. Waltham (MA): Wolters Kluwer. [cited 2025 Nov 11].
- Ilkit M, Durdu M, Karakaş M. Cutaneous id reactions: a comprehensive review of clinical manifestations, epidemiology, etiology, and management. Crit Rev Microbiol. 2012 Aug;38(3):191-202. doi:10.3109/1040841X.2011.645520. Go to original source... Go to PubMed...
- Zabawski EJ Jr, Elston DM. Id Reaction (Autoeczematization). In: Medscape [Internet]. Updated Feb 25 2025. [cited 2025 Nov 11].
- Vignes S, Raffalli-Grego H. Allergic contact dermatitis: Clinical features and diagnosis. In: UpToDate [Internet]. Waltham (MA): Wolters Kluwer. [cited 2025 Nov 11].