Invasive Group A Streptococcus Toxic Shock Syndrome, Myositis, and Probable Necrotizing Fasciitis in Pemphigus Vulgaris

Skin and soft tissue infections are common in pemphigus vulgaris (PV), affecting an estimated 50% of patients. Invasive group A streptococcal infection carries a reported mortality of 70% to 100%. We describe a 44-year-old man with PV who developed invasive group A streptococcal infection with toxic shock syndrome, myositis, and probable necrotizing fasciitis of the right upper extremity that was treated with multidisciplinary care. To our knowledge, this is the first such presentation reported during an active PV flare, highlighting the diagnostic overlap between these entities and the challenges of applying existing treatment guidelines to this uncommon presentation.