iarjmsIARJMSIARJMS2708-3594https://doi.org/10.47310/iarjms.2020.v01i02.027Hailey-Hailey Disease: A Challenging Diagnosis in Biopsy PracticeVladimírBartošKarolínaVorčákováKlaudiaPéčováBackground: Hailey–Hailey disease (HHD) is a rare acantholytic genodermatosis. Establishing the diagnosis is often arduous and strictly depends on adequate clinical history and histopathology results. Case Report: The authors describe a 40-year-old woman, who periodically experienced skin erythema in the axillae and groins, accompanied by intermittent inflammation, secernating and purulent discharge. Last time, she presented with a demarcated erythematous plaque on the left sub-mammary region. Histology revealed an extensive supranasal acantholysis of the epidermis with intraepidermal vesicles and bullae formation. The widespread irregular acantholysis gave rise to the typical “dilapidated brick wall” appearance. Adnexal structures were spared. The microscopic findings were characteristic for HHD and even clinical symptomatology was highly suggestive for this disorder. Conclusion: Although HHD exhibits a typical histomorphology, this is not pathognomonic for it. Therefore, biopsy investigation alone may not be sufficient for the purpose of making a definite diagnosis. HHD is a challenging diagnosis that always requires a comprehensive assessment of both, histopathologic and clinical findings.