Erozive Pustular Dermatosis of Scalp: An Overlooked Entity

Abstract

Clinical Presentation: A 63-year-old female patient presented with erosion, crusting, and scabbing of the scalp for two months. She informed that she had had also alopecia for 10 years. She recalled a trauma on her scalp 15 days ago before the onset of erosions. Dermatological examination revealed the presence of extensive erosion, crusts in areas of scatricial alopecia, with tiny pustules on the sides of the erosion (Figure 1). Potassium hydroxide examination of pustule was negative. No microorganism was observed on bacterial and fungal cultures of pustules. A punch biopsy was performed from the skin lesion and on histopathological examination epidermal acanthosis, spongiosis, neutraophilic infiltration in stratum corneum and dense perivascular inflammatory infiltrates including neutrophil, lymphocyte and eosinophils were detected (Figure 2, HEx10). The clinical and histopathological findings led us a diagnosis of “erosive pustular dermatosis”. The lesions healed completely with a 2-week topical mometason furoate treatment (Figure 3). Erosive pustular dermatosis of the scalp is a rare condition characterized by sterile pustules, erosions, atrophy and crusted lesions on the scalp of skin . It usually develops in sun-damaged skin of elderly people with alopecia [1]. Although the etiology of the condition remains unidentified, it has been suggested to be triggered by local trauma such as incidental trauma, surgical procedures, skin graft, hair transplantation, physical or chemical procedures like topical retinoid, imiquimod, radiotherapy, cryotherapy, photodynamic therapy (PDT), or laser therapy. Erosive pustular dermatosis of the scalp can be misdiagnosed for other conditions like bacterial or fungal infections, inflammatory diseases such as IgA pemphigus, pustular psoriasis, cicatricial pemphigoid, actinic keratosis, or even squamous cell carcinoma [1,2]. Herein, a case of erosive pustular dermatosis with an onset after trauma is presented. We emphasize that clinicians should be aware of this entity not to misdiagnosis as other inflammatory and neoplastic entities.