Semiconductor Laser-Assisted Therapy For Drug-Induced Erythema Multiforme

We present a case of drug-induced erythema multiforme (EM), emphasizing the adjunctive role of semiconductor laser in optimizing EM therapy. A 55-year-old male presented with with lip, oral, skin and genital erosions and skin target erythema for one month after taking “Gankang”. Laboratory tests excluded infections. The diagnosis is erythema multiforme. Management included immediate discontinuation of "Gankang," oral prednisone (30 mg/day, tapered over 4 weeks), loratadine (5 mg/day for 7days), and 0.5W semiconductor laser therapy (1 minute/spot) targeting lip/oral lesions, combined with topical erythromycin, dexamethasone mouthwash, and fluticasone propionate cream). Laser therapy immediately alleviated pain and exudation. Mucosal healing progressed markedly within 7 days, with complete resolution at 4 weeks following steroid. While infections are the most common predisposing factor for EM, this case identifies medication as the definitive cause, emphasizing the necessity of comprehensive medication review. Semiconductor laser therapy demonstrated adjunctive efficacy by suppressing inflammatory exudation, alleviating pain, and accelerating mucosal healing through photobiomodulation. Although systemic glucocorticoids remain the cornerstone of EM therapy, laser intervention synergized with steroid therapy by enhancing tissue regeneration and reducing inflammation, thereby lowering cumulative steroid exposure and shortening treatment duration. This combined treatment approach not only controls symptoms in a timely manner, but also reduces the risk of prolonged steroid use to some extent. This multimodal strategy—integrating causative drug discontinuation, systemic glucocorticoids, topical medication, and semiconductor laser—achieved rapid mucosal healing with reduced cumulative steroid exposure, offering a synergistic protocol for treating severe EM.