Refractory Eczema as a Presenting Feature of Common Variable Immunodeficiency

Common variable immunodeficiency (CVID) is the most prevalent symptomatic inborn error of immunity (IEI) in adults. It presents with recurrent infections and non‐infectious complications, including autoimmunity, lymphoproliferation and dermatitis. Despite skin involvement being reported in up to 40% of patients, eczema as an initial manifestation is often underrecognized. We report a case of a 32‐year‐old woman with chronic, treatment‐refractory eczema, who was ultimately diagnosed with CVID. Her skin lesions, affecting the face and trunk, responded only transiently to topical therapy. Laboratory evaluation identified low IgG, IgA and IgM, with a marked IgG2 and IgG4 subclass deficiency. Flow cytometry showed a profound B‐cell maturation defect, and pneumococcal vaccination response was absent. Secondary causes of immunodeficiency were excluded. Based on these findings, a diagnosis of CVID was established. Immunoglobulin replacement therapy (IGRT) was initiated, leading to clinical improvement of eczema alongside topical therapy. This case highlights that eczema, particularly when atypical, treatment‐resistant and accompanied by infections or lymphadenopathy, can be the presenting feature of CVID. Recognition of this association is critical for timely diagnosis and appropriate management.