Toxic rash associated with high dose methotrexate therapy.
Fifteen rashes were observed in thirteen patients in association with high dose methotrexate therapy. The lack of recurrence of the rash with further treatment courses and the association of the rash with other toxic manifestations and with larger doses of methotrexate suggests a toxic mechanism. Rashes have frequently been reported in association with dose methotrexate therapy (Van Scott, Auerbach & Weinstein, 1964; Leone, Albala & Rege, 1968; Mitchell et al., 1968; Capizzi et al., 1970; Jaffe et al., 1973; Rosen, Suwansirikul & Kwon, 1974; Pratt et al., 1975; Jaffe & Traggis, 1975; Ensminger & Frei, 1977; Stoller et al., 1977). They include perifolliculitis, transient erythema progressing to maculopapular eruptions, occasionally desquamating, sloughing over pressure areas, reactions confined to radiation portals, exacerbation of acne, photosensitivity and rarely urticaria. Relatively few reports sufficiently document the incidence or types of rash. It has been suggested that the rash is allergic in nature (Mitchell et al., 1968) or a toxic phenomenon (Djerassi et al., 1972; Djerassi & Kim, 1976), possibly related to drug effects on small vessels (Van Scott, 1963).