Investigation of underlying primary immunodeficiencies in patients with severe atopic dermatitis.

BACKGROUND Primary immunodeficiency diseases (PIDs) are a group of heterogeneous inherited disorders, characterised by recurrent infections, autoimmunity and malignancy. Some PIDs such as hyper IgE syndrome (HIES) and Wiskott-Aldrich syndrome (WAS) may be initially presented as atopic dermatitis (AD), especially in its severe form, resulting in diagnostic delay and poor prognosis of patients. OBJECTIVE The aim of this study was to evaluate the frequency of PIDs among patients with severe AD and to determine factors that can help to raise suspicion towards these disorders. METHODS Seventy-five patients with a well-established diagnosis of severe AD were enrolled in this study. Initial immunological evaluations, including humoral and cellular investigation, were performed in all individuals. Patients underwent further investigations in a case of suspicion of a probable PID. RESULTS Among all patients with severe AD, five (6.6%) were diagnosed with HIES and one (1.3%) with WAS. Family history of PIDs, family history of death in early infancy, positive history of recurrent infections such as skin and respiratory infections, otitis media and sinusitis were observed significantly higher in patients with a diagnosis of PID. CONCLUSIONS The presence of an underlying PID could explain the poor prognosis and refraction to the treatment of some patients with severe AD. Several clinical and laboratory findings can help the physicians to focus towards PIDs which are more serious. Delay in diagnosis of PID cases with skin manifestation of AD without proper management may result in lower quality of life and higher morbidity and mortality rates.