[The disease under chronic urticaria: beyond itching]

Brief erythematous-papular skin rashes suggest the diagnosis of urticaria; However, it may be another type of dermatitis, and complementary examinations must be carried out to establish its diagnosis.

53-year-old female patient, diagnosed in 2016 with diffuse large B cell lymphoma, in complete remission. Since 2010, he has had episodes of erythematous-papular lesions lasting 24-36 hours. He received antihistamines, corticosteroids and omalizumab without clinical improvement. The ANA determination was positive (1/320), nuclear mitotic pattern. The skin biopsy was compatible with dermatitis herpetiformis. The study of celiac and locus antibodies showed positivity for HLA-DQ2 and DQ2.5 in heterozygosity. The diagnosis of dermatitis herpetiformis was established. Treatment consisted of a gluten-free diet and prescription of dapsone, with satisfactory results.

It is important to establish the differential diagnosis of patients with chronic urticaria who do not respond to the reference treatment, in addition to carrying out a thorough clinical examination and physical examination before starting treatment and relying on a multidisciplinary team to establish an accurate diagnosis and treatment. appropriate. Due to the side effects of dapsone, subsequent follow-up of patients is essential.