Atezolizumab Induced Generalized Cutaneous Lichen Planus in a Patient With Metastatic Small Cell Lung Cancer Successfully Treated With Isotretinoin : A Case Report .

17 FEBRUARY 2025 .

Immune checkpoint inhibitors, now widely used in treating various malignancies, increase the risk of autoimmune reactions and immune-related adverse events (irAEs), with skin toxicities being the most frequent .

These agents enhance the immune response against tumors by blocking the suppression of cytotoxic T lymphocytes .

Here, we report a rare case of generalized cutaneous lichen planus induced by ATEZOLIZUMAB, an immune checkpoint inhibitor administered for SMALL CELL LUNG CÁNCER .

 After consulting with the oncologist, we opted to initiate isotretinoin as the first-line treatment .

 Considering the patient's oncologic status and multiple comorbidities, we aimed to avoid systemic corticosteroids due to their potential side effects .

This case was effectively managed with low-dose oral isotretinoin alongside high-potency topical corticosteroids. It emphasizes the need to consider retinoids as a potential treatment option for various dermatological conditions beyond acne .

 Isotretinoin may be beneficial in treating lichen planus by influencing cellular proliferation and promoting epithelial differentiation, though its exact mechanism remains uncertain .

 Additionally, it has notable anti-inflammatory effects and modulates immune responses. In such cases, isotretinoin may also enhance the therapeutic effects of topical corticosteroids through a synergistic interaction .