Abstract
BACKGROUND: We present a rare case of TNF-α inhibitor induced pigmented purpuric dermatoses (PPD) and explore its mechanisms and management. CASE PRESENTATION: A 44-year-old woman presented with non-pruritic non-tender petechial rash on bilateral lower limbs after being started on Adalimumab, with the rash progressing to worsen on Golimumab, both used for managing her seronegative peripheral arthritis. Laboratory panel revealed a negative vasculitis screen and skin biopsy confirmed the condition. After ceasing the TNF-α inhibitors and changing to Secukinumab, an Interleukin-17 inhibitor, the lesions stopped erupting and slowly resolved. CONCLUSION: PPD is a benign skin condition and has been associated with various medications and exposure to chemicals in the literature. Different mechanisms have been proposed in the literature however its exact aetiology is unknown. To date, there is no standardized treatment however patients should be reassured that PPD is benign and will often regress by itself once the causative agent has been removed.