[The disease under chronic urticaria: beyond itching].

Background: 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.
Case Report: 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.
Conclusion: 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.