Ceftriaxone induced fixed drug eruption in patient with common variable immunodeficiency

Adverse drug reactions are one of the most complex and difficult diagnostic problems in the practice of allergists and clinical immunologists. This article presents a clinical case of a patient with an inborn error of immunity, known as common variable immune deficiency with the onset of the disease in adulthood and the presence of numerous infectious, structural, and immune complications. The patient had an adverse drug reaction represented by fixed drug eruption to the vital antibiotic therapy with ceftriaxone. We provide detailed information about this type of drug allergy and the structural features of cephalosporins and their cross-reactivity. In the diagnostic process, we ran phased drug allergy testing, including patch tests and a dose provocative test, which is considered a gold standard for this type of diagnostics. The diagnosis of fixed drug eruption to ceftriaxone and the absence of cross-reactivity to other cephalosporins in this patient were confirmed based on test results. Prohibiting the use of only one drug (ceftriaxone), which is especially important for a patient with primary immunodeficiency was made possible due to the compiled individual recommendations.