Lues maligna, also known as malignant syphilis, is an uncommon variant of syphilis at the secondary stage – more commonly reported in immunocompromised patients or those with concomitant human immunodeficiency virus (HIV) infection. In this report, we present a case of a 28‑year‑old HIV‑negative male with a 9‑month history of multiple, well‑defined, irregularly‑shaped, erythematous papules, and small plaques evolving to ulcerated plaques and nodules with crusts, associated with pain, pruritus, and episodes of fever, arthralgia, and weight loss. Positive treponemal and nontreponemal tests, aided by histopathologic findings consistent with syphilis led to the diagnosis of lues maligna. Significant improvement of lesions was noted with 3 weekly doses of 2.4 million units of benzathine penicillin G. For patients presenting with painful and pruritic erythematous ulcerated plaques with crusts associated with systemic symptoms, and with a significant sexual history despite testing negative for HIV infection, a high index of suspicion for uncommon presentations of other sexually transmitted infections such as syphilis could aid in early diagnosis and subsequent treatment.

Introduction: Pemphigus vulgaris is a life-threatening, autoimmune bullous disease caused by desmogleins (Dsg) 1 and 3 au- toantibodies. It is a rare disease with an incidence rate of 0.5 to 3.2 per 100,000 per year. It typically presents as painful, flaccid blisters and erosions on both the skin and mucous membranes. Case report: We present a 43-year-old male with painless penile erosions of 1-month duration. He was evaluated for sexually transmitted infections, but laboratory tests yielded negative results. Subsequently, vesicles and bullae on the back and hyper- keratotic lesions on the malar area appeared, leading to the differential diagnoses of bullous diseases. Skin biopsy was done revealing intraepidermal suprabasal blisters with acantholytic cells. Direct Immunofluorescence demonstrated positive inter- cellular deposits of IgG and C3. ELISA Dsg 1 and Dsg 3 were positive (ratio of 1.857 and 4.580, respectively). A final diagnosis of pem- phigus vulgaris (PV) was made. The patient has remained in remission after a 3-month course of prednisone and azathioprine. Conclusion This is a unique case of PV presenting with an unusual manifestation of painless penile erosions. There have been limited reports of PV with penile skin involvement and all cases presented with painful lesions. Because painless penile lesions as presenting feature is rare, the diagnosis may be easily missed. This case demonstrates that thorough dermatologic examination and early diagnosis despite atypical findings are crucial to provide timely and appropriate treatment as this determines the clinical outcome of the disease.
Pemphigus ; Desmogleins ; Azathioprine