SKIN May 2022 Volume 6 Issue 3 (c) 2022 THE AUTHORS. Published by the National Society for Cutaneous Medicine. 269 SKIMages Pustular Penile Pyoderma Gangrenosum: A Puzzling Clinical Presentation Mezni Line, MD1, Elhadadi Farah, MD1, Ismaili Nadia MD,PhD1 1Ibn Sina University Hospital Dermatology Department, Mohammed V University, Rabat, Morocco Figure 1 : Penile pyoderma gangrenosum : erosive, and sharply demarcated lesions on the glans penis Pyoderma gangrenosum (PG) is a recurrent, chronic inflammatory neutrophilic dermatosis. It is usually associated with an underlying systemic disease such as inflammatory bowel disease and hematological malignancy. PG may occur SKIN May 2022 Volume 6 Issue 3 (c) 2022 THE AUTHORS. Published by the National Society for Cutaneous Medicine. 270 Figure 2: Biopsy of the glans showing an ulcerated epidermis ,fibrinous exudate, neovascularization, and an acute inflammation beneath characterized by a dense and diffuse, predominantly neutrophilic infiltrate ( H&E x100) anywhere on the body while it is classically described on the lower extremities1. A healthy 60-year-old Moroccan man developed a persistent, erythematous vesiculo-pustular erosive, and sharply demarcated lesions on the glans penis (Figure 1). The patient denied extramarital sex and no relevant medical history has been reported. Further physical examinations were unremarkable. The lesions were unresponsive to topical fusidic acid 2% cream twice daily for a period of 2 weeks. The skin biopsy showed patterns of PG (Figure 2) and tissue cultures were negative for bacteria, mycobacteria, and fungus infection, full blood screening was normal. Topical clobetasol propionate 0.05% was prescribed once daily for 4 weeks and every other day for 4 weeks resulting in a complete resolution. The follow-up period was marked by a recurrence after 8 months, lesions were treated with topical tacrolimus 0.1% once daily for 1-month and completely healed after 2 weeks. Four clinical variants of pyoderma gangrenosum have been described: ulcerative, bullous, vegetative, and pustular. Frequently, one form of PG is seen in a patient and up to 25% of patients recall a history of pathergy phenomenon (the abnormal development of skin lesions at the sites of trauma, including minor injuries)1. The pustular form is a rare variant showing painful vesiculo-pustular lesions that don’t ulcerate and are commonly observed on the trunk and on the extensor surfaces. Histopathology shows a dermal neutrophilic infiltrate and subcorneal neutrophilic micro pustules. It is commonly observed in patients with active ulcerative colitis. Only a few cases have been reported in the literature and were associated with hyperglycemia and https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4553856/#ref1 SKIN May 2022 Volume 6 Issue 3 (c) 2022 THE AUTHORS. Published by the National Society for Cutaneous Medicine. 271 hyperlipidemia. The diagnosis might be challenging as there are no specific histopathologic or immunofluorescent features and it is mainly based on clinical hallmarks, the association with systemic diseases and the exclusion of differential diagnosis. Topical tacrolimus therapy is effective and is recommended as a first-line modality2. Surgical debridement is not recommended in the acute stage due to the risk of tissue progression3. Hence, we report the first case of pustular penile pyoderma gangrenosum without an underlying disease successfully treated by topical monotherapy. Conflict of Interest Disclosures: None Funding: None Corresponding Author: Mezni Line, MD Av Lamfadel Cherkaoui 10100 Rabat, Morocco Phone : (+212) 642-657-940 E-mail : mezni_line@outlook.com References: 1. Shankar S, et al. Pustular pyoderma gangrenosum. Clin Exp Dermatol 2003; 28:600 2. Larsen CG, Thyssen JP. Pustular penile pyoderma gangrenosum successfully treated with topical tacrolimus ointment. Acta Derm Venereol 2012;92:104-5. 3. Chia MW, et al. Pustular pyoderma gangrenosum: an uncommon variant which is easily misdiagnosed. Dermatol Online J 2008 14: 21