Platelet-to-lymphocyte ratio predicts the duration of glucocorticoid therapy in the treatment of cutaneous adverse drug reactions

Glucocorticoid (GC) remains the mainstay of treatment for cutaneous adverse drug reactions (cADRs) but has been associated with side effects, emphasizing the importance of precisely managing the duration of high-dose GC treatment. Although the platelet-to-lymphocyte ratio (PLR) has been proven to be closely related to inflammatory disorders, its ability to predict the timing of GC dose reduction (Tr) during cADRs treatment remains obscure. Hospitalized patients diagnosed with cADRs treated with glucocorticoids were analyzed in the present study to evaluate the association between PLR values and Tr values using linear, locally weighted scatter plot smoothing (LOWESS) and Poisson regression. Subgroup and ROC curve analyses were conducted to identify confounding variables and assess the predictive performance, respectively. A total of 308 patients were included in the study, with a median age of 47.0 (31.0–62.0) years old and a median incubation period of 4 days. Antibiotics (n = 113, 36.7%) were the most common cause of cADRs, followed by Chinese herbs (n = 76, 24.7%). PLR values were positively correlated with Tr values during linear regression (P