[Round Table: Urticaria in relation to infections].

OBJECTIVES: 1) To study the clinical and analytic features of infectious disease associated to urticaria in children. 2) To look into the probable etiology of the infectious disease. 3) To determine atopic predisposition and previous urticarial episodes and to rule out the involvement of antibiotics.
DESIGN: Transversal and observational study.
SETTING: Pediatric Allergy Outpatient Clinic of a tertiary Hospital. PATIENTS: Forty-four children, aged 1 to 12 years with acute urticaria associated to clinically infectious or febrile illness attending an Emergency Pediatric Department. INTERVENTION: Symptoms evaluation and physical examination in the seventh first days and follow over 3-6 weeks by the same physician. MEASUREMENTS: Clinical features of urticaria (duration, angioedema associated); Clinic diagnosis of illness infectious (acute respiratory infection, gastroenteritis, febrile syndrome); white blood cells count, C-reactive protein, aminotransferases (AST, ALT), L-Y-glutamyl transferase; viral culture and antigen detection: enterovirus (EV), adenovirus, respiratory syncytial virus (RSV), parainfluenza 1, 2 and 3, influenza A y B and cytomegalovirus (CMV); serological assay: CMV, enterovirus, mycoplasma pneumoniae, Epstein-Barr, parvovirus B19. RESULT: 22 children (50%) are between 1-2 years old. 40 patients (90,9%) had symptoms of respiratory tract infection and only four patients had a pneumonia. The other 4 children had a gastroenteritis. The analytic was suggestive of viral infection in 35 (79.5%) and unknown on seven patients. In 20 children (45.4%) was identified a probable infection. The viral detection was positive in 3 patients: CMV, herpes simplex 1 and influenza A. Twenty microbiological findings for seventeen patients was found by serological criterion of probable infection: enterovirus (10); parvovirus B19 (4); Epstein-Barr (3) y mycoplasma (3). Evidence of a double serologic infection was found in three patients. In comparison with a serological control group encountered that acute urticaria during a infectious disease is significantly associated (p = 0.0054) to high titer to enterovirus by complement-fixation. The urticaria was associated with angioedema in 38.6% and 9 children (20.4%) related an previous similar episode. Twenty-one (47.7%) had been treated with antibiotics before development the urticaria. All patients was given the suspected antibiotic and no patient developed any adverse reaction.
CONCLUSIONS: The clinically infectious associated to urticarial rash in children, usually is a viral respiratory infections. Is more frequent at infant. In spite of antibiotic therapy is often related to development the urticaria, the subsequent challenge with the same antibiotic is good tolerated.