Methotrexate Cutaneous Ulceration: A Systematic Review of Cases

Methotrexate cutaneous ulceration is a rare methotrexate complication, and has only been described in case reports and case series.

To document patient characteristics, morphologic features, and mortality risk factors for methotrexate cutaneous ulceration.

A systematic literature review of PubMed and Embase (last date 1 November 2021) was performed with data collected from case reports and case series. This study was limited to cases of cutaneous ulceration; presence of oral ulceration was collected from within these cases.

114 cases (men = 57.9%, mean age = 61 years) of methotrexate cutaneous ulceration met inclusion criteria. Psoriasis (69.3%), rheumatoid arthritis (18.4%), and mycosis fungoides (6.1%) were the most common indications for methotrexate use. Morphologies included erosions localized to psoriatic plaques (33.3%), epidermal necrosis/necrolysis (35.1%), localized ulceration (16.7%), and skin-fold erosions (5.3%). Methotrexate dose preceding toxicity varied greatly; median 20 mg/week, interquartile range 15-40 mg/week, range 5-150 mg/week. Most patients had risk factors for serum toxicity (baseline renal dysfunction = 37.8%, concurrent NSAID use = 28.1%, inadequate folic acid use = 89.1%). Thirty percent of cases involved mistakenly high methotrexate doses. Fourteen patients (12%) died. Absence of folic acid use (69% vs. 100%, p value < 0.001), pancytopenia (33% vs. 86%, p value < 0.001), and renal dysfunction at presentation (47% vs. 92%, p value < 0.001) were associated with increased mortality.

Selection bias present due to abstraction from case reports and case series.

Methotrexate cutaneous ulceration is commonly preceded by dosage mistakes, absence of folic acid supplementation, and concurrent use of nephrotoxic medications. Renal impairment, pancytopenia, and absence of folic acid supplementation are key risk factors for mortality from this adverse medication reaction. Providers should regularly monitor methotrexate dosing adherence, drug-drug interactions, and perform routine laboratory evaluation. Index of suspicion for this toxicity should remain high given the varied clinical presentation and high mortality.