Urticaria multiforme in childhood and investigation of its association with mycoplasma pneumoniae infection

Abstract

Background and Design: Urticaria multiforme is a rare clinical and morphological subtype of acute urticaria in childhood. Clinical features include acute onset of blanchable, annular, polycyclic, erythematous wheals with dusky or ecchymotic centers (target lesion-like). Pruritus nearly in all cases and edema on the face, hand and foot in the majority of them are seen. Even though urticaria multiforme is known as a benign cutaneous hypersensitivity reaction, the existing body of knowledge regarding its aetiology and pathogenesis of the disease is yet unclear. This study aimed to investigate the clinical and laboratory features children diagnosed with urticaria multiforme and its association with Mycoplasma pneumoniae infection.Materials and Methods: The examination of clinical features and laboratory findings (in addition, serological tests for Mycoplasma pneumoniae, rubella, parvovirus B19, herpes simplex, hepatitis B virus, hepatitis C virus, Epstein-Barr virus, cytomegalovirus, varicella zoster virus) of a total of four cases diagnosed with urticaria multiforme and its association with Mycoplasma pneumoniae infection were investigated. Skin biopsy findings of two cases whose informed consent were obtained were recorded.Results: Ages of the cases ranged between 1.5 and 4 and the ratio of male-female patients was 1 (2/2). All the patients had pruritus; blanchable, annular, polycyclic, erythematous wheals with dusky or ecchymotic centers (target lesion-like) on the skin; and edema on the face and/or acral regions. Before the skin findings commenced, all the cases had fever; two had lower respiratory tract and other two had upper respiratory tract infections. The patients had the history of the use of drugs such as amoxicillin/clavulanic acid, ibuprofen, paracetamol, cefdinir, oxolamine citrate and chlorpheniramine maleate. The skin biopsy findings were found to be compatible with urticaria multiforme. While Mycoplasma pneumoniae IgM were positive in of the two cases (50%), all the serologic tests were normal in the remaining two.Conclusion: As a result of the clinical and serological detection of Mycoplasma pneumoniae infection in two cases with urticaria multiforme, it was thought that a cutaneous hypersensitivity reaction against microbial antigens could play a role in the development of the disease. It is important to have differential diagnosis of urticarial multiforme especially between serum-sickness-like reactions and erythema multiforme.