Angelica Selim, MD

Two takes on a condition that can be difficult to pin down and resistant to treatment

Urticarial dermatitis (UD) was first defined 8 years ago. It is characterized by pruritic erythematous papules and plaques resembling urticaria but enduring longer than 24 hours. An association with eczematous lesions is possible. Biopsy samples show normal stratum corneum, minimal spongiosis, and papillary dermal perivascular lymphocytic inflammation with eosinophils; neutrophils may be present. This is a detailed study of patients with clinical and biopsy-proven UD.

These authors retrospectively analyzed clinical and laboratory evaluations and final diagnoses in 146 patients with a clinical diagnosis of UD. Mean age and duration of disease at presentation were 60 years and 1 year, respectively; 60% were women. Nearly all patients had truncal lesions and most had affected extremities. A final diagnosis of UD was rendered in 70 patients (40 with both clinical and histopathologic signs). The rest received diagnoses of dermatitis not otherwise specified, urticaria, drug reaction, bullous pemphigoid, atopic dermatitis, contact dermatitis, scabies, pruritic urticarial papules and plaques of pregnancy, and others. Among patients with a final UD diagnosis, 4 had a new malignancy within 4 months of UD onset, and 18% had autoimmune disease (rheumatoid arthritis, autoimmune hepatitis, Crohn's disease, multiple sclerosis, and vitiligo). Treatment included oral antihistamines, topical corticosteroids, narrowband ultraviolet-B phototherapy, prednisone, and topical calcineurin inhibitors. Multiple and variable treatment modes and varying follow-up made treatment response difficult to measure, but nearly half of patients had no response.

Citation(s):

Hannon GR et al. Urticarial dermatitis: Clinical features, diagnostic evaluation, and etiologic associations in a series of 146 patients at Mayo Clinic (2006-2012). J Am Acad Dermatol 2014 Feb; 70:263.