Successful treatment of multiple plantar warts complicated by systemic lupus erythematosus with ALA-PDT, a case report

• We reported a rare case of multiple plantar warts complicated by systemic lupus erythematosus (SLE). • The plantar warts were extensive, fusing into a plaque with a large size of 7 × 3 cm, and conventional treatments over the past four years repeatedly ending in failure. • Four rounds of ALA-PDT cured the plantar warts with no recurrence in one year of follow-up. • ALA-PDT is a safe and effective method for patients who suffer from intractable multiple plantar warts complicated by SLE. Plantar warts are common skin neoplasms caused by human papillomavirus (HPV) infection. Patients with immunocompromised conditions often have a higher prevalence of HPV infection-induced skin warts, with recalcitrant nature to various options of treatment. Here, we diagnosed a case of multiple and coalesced plantar warts complicated by Systemic Lupus Erythematosus (SLE) which persisted for years and was refractory to conventional treatment. Following superficial shaving to remove the thickened corneum, we initiated 5-aminolevulinic acid - photodynamic therapy (ALA-PDT). After four rounds of the treatments within two months, the lesions were completely cleared with no recurrence in one year of follow-up.