Successful treatment of multiple Keratoacanthoma by 5-aminolevulinic acid-mediated photodynamic therapy: Case experience

Keratoacanthoma (KA) is considered as a variant of cutaneous squamous cell carcinoma. A 51-year-old male presented with multiple itchy papules and plaques on his head and face for 8 months. He received cryotherapy, laser therapy, and topical treatment with tretinoin before, however, it did not work. He is very distressed because of itching and increased lesions. His past medical history included skin malignant melanoma with lung and bone metastases since 5 years ago, which recurred after surgically resected. In addition, he received immunotherapy, including Trastuzumab, Osimertinib and PDL-1 inhibitors. And histopathology result was consistent with the diagnosis of KA. The patient received 3 sessions of AlA-PDT at 2-week intervals. After 3 sessions of AlA-PDT, all lesions disappeared completely. At 2-years follow up, there was no recurrence. This case suggests that photodynamic therapy is good treatment option for multiple or eruptive KA.