Montenegro Skin Test and Age of Skin Lesion as Predictors of Treatment Failure in Cutaneous Leishmaniasis

Abstract

A case-control study was conducted to examine the association among the Montenegro skin test (MST), age of skin lesion and therapeutic response in patients with cutaneous leishmaniasis (CL) treated at Evandro Chagas National Institute of Infectious Diseases (INI), Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro, Brazil. For each treatment failure (case), two controls showing skin lesion healing following treatment, paired by sex and age, were randomly selected. All patients were treated with 5 mg Sb5+/kg/day of intramuscular meglumine antimoniate (Sb5+) for 30 successive days. Patients with CL were approximately five times more likely to fail when lesions were less than two months old at the first appointment. Patients with treatment failure showed less intense MST reactions than patients progressing to clinical cure. For each 10 mm of increase in MST response, there was a 26% reduction in the chance of treatment failure. An early treatment - defined as a treatment applied for skin lesions, which starts when they are less than two months old at the first appointment -, as well as a poor cellular immune response, reflected by lower reactivity in MST, were associated with treatment failure in cutaneous leishmaniasis.

Favorable responses to treatment with 5 mg Sbv/kg/day meglumine antimoniate in patients with American tegumentary leishmaniasis acquired in different Brazilian regions

“…Based on these observations, MA 5 mg Sb v /kg/day IM or IV was successfully administered in up to three 10-day series interspersed with 10-day periods without medication for CL treatment in patients above 60 years, those with comorbidities, or after discontinuation of systemic treatment due to adverse effects 22 . In different series of cases of CL 18,19,20,23 or ML 20 patients treated with 5 mg Sb v /kg / day MA, the frequency of successful treatment varied between 80 and 86%. These responses were similar to the efficacy of 76.5% reported for the conventional dose of 20 mg Sb v / kg / day 9 , but with a lower frequency of adverse effects 24 .…”

Clinical and laboratory profiles of patients with early spontaneous healing in cutaneous localized leishmaniasis: a historical cohort study

“…It has also been reported that early treatment of ACL does not prevent the development of ulcers [25, 26] and is associated with higher treatment failure rates [26]. Short evolution times prior to treatment and weak positive MST were both associated with treatment failure [27]. Other factors have also been found to be able to influence the therapeutic response to PA.…”

Evaluation of the reference value for the Montenegro skin test

“…Nine (1.2%) patients and 11 (1.4%) patients with lesion durations >2 months presented negative MST results, depending on the cut-off (5mm and 6mm, respectively). A negative response with the MST after 2 months of disease evolution might be related with a defect of the host immune response (23) . The ROC curves that were constructed according to sex showed higher sensitivity for men, which supports the fi ndings of a previous study (26) , while higher specifi city was found for women for both cut-off points.…”