Selective
immunoglobulin E deficiency (SIgED) is still an unrecognised primary immunodeficiency despite several observations supporting its existence. This study aimed to describe the
skin manifestations associated with SIgED. We retrospectively assessed medical records of patients with SIgED, the diagnosis being based on serum
IgE levels ≤2 Uk/L associated with normal serum levels of
immunoglobulins G, M, and A. A total of 25 patients (24 female) with SIgED were included in the study. Eleven patients (44%) presented
chronic spontaneous urticaria (CSU), five (20%)
angioedema always associated with CSU, five
erythema (20%), and six
eczema (24%). Other, less frequent manifestations were
lichen planus,
anaphylactoid purpura,
thrombocytopenic purpura,
bullous pemphigoid, bullous
pyoderma gangrenosum, and atypical skin lymphoproliferative infiltrate associated with reactive
lymphadenopathy, chronic
cholestasis,
arthritis, and
fibrosing mediastinitis. Fifteen patients (60%) had different types of associated
autoimmune diseases, Hashimoto's
thyroiditis being the most frequent (n = 5, 20%), followed by
arthritis (n = 4, 16%),
autoimmune hepatitis,
neutropenia,
vitiligo, and Sjögren's syndrome (n = 2, 8% each). Five
malignancies were diagnosed in four patients (16%). An ultralow
IgE serum level may be the only
biomarker that reveals the presence of a dysregulated immune system in patients with a broad spectrum of
skin manifestations.