Efficacy and tolerability at 3 and 6 months following use of azathioprine for recalcitrant atopic dermatitis in children and young adults

Introduction: Recalcitrant childhood atopic dermatitis (AD) causes significant morbidity and may necessitate systemic treatment with immunomodulating agents such as azathioprine. We reviewed the clinical and biochemical effects of this agent in children and adolescents receiving this treatment between November 2005 and December 2007. Methods: The clinical efficacy of azathioprine, and its hematological and biochemical effects (serum IgE level, liver and renal function), were assessed at 3 months and 6 months in 17 cases of recalcitrant AD. Disease severity was evaluated with the SCORing Atopic Dermatitis (SCORAD) score which has two components, namely (1) the objective SCORAD which measures the extent (percentage of body surface area involved) and intensity of the lesions, and (2) visual analog scales which measure the subjective symptoms of pruritus and sleep loss. Results: There were nine males and eight females with a mean (SD) age of 16.1 (3.9) years. Compared with baseline, significant improvements were observed at 3 months (n = 17) and 6 months (n = 16) in SCORAD (p = 0.002; p < 0.001), objective SCORAD (p = 0.002; p = 0.001), extent (p = 0.001; p < 0.001), pruritus (p = 0.004; p = 0.00 1) and dryness (p = 0.033 at 6 months). Compared with males, objective SCORAD was significantly lower in females (p = 0.009) at 6 months. Azathioprine was stopped in one female after 4 months due to lack of efficacy. Serum total IgE (p = 0.006) was significantly lower at 6 months. The frequency of oral antihistamine usage and Staphylococcus aureus carriage were also significantly reduced (p = 0.031 and p = 0.016, respectively). Mild transient elevation of glutamic-pyruvic transaminase in one patient which became normalized on cessation of the drug, and mild elevation of serum bilirubin in two other patients were observed. Conclusions: Azathioprine reduced the disease severity of AD within 3 months of use in these children. Better efficacy was observed in females at 6 months. Adverse hematologic and biochemical effects appeared acceptable but longer-term monitoring is desirable.