Severe Pustular Lesions Induced by Topical Immunotherapy with Squaric Acid Dibutylester for Alopecia Totalis

Two cases of severe pustular lesions were reported following the use of squaric acid dibutylester (SADBE) for treating alopecia totalis. Both patients, who had allergic conditions, developed itchy erythema and pustular lesions shortly after SADBE application. The first case involved a 41-year-old female who responded well to a lower concentration of SADBE after initial adverse reactions, while the second case involved a 39-year-old female who also required systemic prednisolone treatment. The study suggested that cytokine imbalances and Th17 cells might contribute to severe pustulation, highlighting the need for caution in patients with allergic predispositions.