Subcutaneous injection of biologics to the lower legs may be a therapeutic option for recalcitrant psoriatic lesions on the lower legs, according to a case study published in the Journal of Dermatology.
Although the use of biologics for the treatment of psoriasis has dramatically improved clinical outcomes, skin lesions in certain body sites such as the anterior lower legs may still be refractory, even to biologics. In these cases, additional treatment with a topical steroid or a biologic switch may be considered. Although biologics are usually administered by subcutaneous injection to the abdomen or upper arm, the difference in the effect depending on injection sites is unclear.
A 57-year old man diagnosed with psoriatic arthritis for 16 years presented with recalcitrant psoriatic lesions on the anterior lower legs. Previous failed treatments included topical steroid and vitamin D3, cyclosporin, etretinate, ustekinumab, and adalimumab. For the past 3 years, the patient had been treated with secukinumab to the abdomen (300 mg per 4 weeks) combined with topical ointment (maxacalcitol and betamethasone butyrate propionate), which significantly improved his joint pain and most of his skin lesions, except for the lesions on the anterior lower legs. He suggested injecting the secukinumab closer to these residual lesions, and improvement of the skin on the anterior lower legs was observed 4 weeks later and had almost disappeared by 16 weeks. Use of the topical ointment was unchanged, and no adverse events were reported.
The authors concluded that, “Although it is limited to a single case using secukinumab and the mechanism remains unclear, the injection of biologics to the lower legs may be a therapeutic option for recalcitrant lesions on the lower legs.”
Katsuo K, Honda T, Kabashima K. Improvement of recalcitrant psoriatic lesions on the lower legs by changing the injection site of secukinumab from the abdomen to lower legs [published online November 1, 2019]. J Dermatol. doi:10.1111/1346-8138.15159