Uncommon local reaction at the injection site of subcutaneous methotrexate

Methotrexate injection site reactions: Case report and literature review

“…Injection site reactions have been reported in patients with seronegative knee arthritis, psoriasis, psoriatic arthritis, and dermatomyositis. [2][3][4][5] To our knowledge, reactions in patients with eosinophilic fasciitis have not been previously described. Lesion characteristics and histologic findings have varied among patients, including the rare finding in one report of an associated B-cell lymphoma.…”

“…Three patients, including ours, have had scaling associated with their lesions. 2,4 Most reported reactions have occurred in the abdomen, likely given that patients typically prefer this location for injections. In contrast, our patient injected her thighs to avoid the diffuse abdominal skin induration.…”

“…Three cases have reported the discontinuation of subcutaneous MTX. 2,4,5 Two of these 3 patients initiated oral MTX administration, and one concomitantly utilized topical antibiotics and steroids. 2,4 Two additional patients noted improvement with topical steroid use.…”

“…1 Injection site reactions associated with the subcutaneous use of MTX are rare but have been previously reported in patients with seronegative knee arthritis, psoriasis, psoriatic arthritis, and dermatomyositis. [2][3][4][5] Although MTX is a mainstay of treatment for eosinophilic fasciitis, injection site reactions in this patient population have not been previously described. Here, we report a case of MTX injection site reactions in a patient with eosinophilic fasciitis and review prior reports of similar reactions.…”

Injection site reaction with subcutaneous methotrexate

“…Similar MTX-induced ISRs to our case have been reported in two patients. 4,5 Both of them developed erythematous skin lesions with crusting and scaling at the injection sites several months after starting the treatment. In both cases, it was decided to switch to oral MTX and the lesions resolved without recurrences.…”