Leishmaniasis Recidivans in Pediatric Patients
LR is a rare clinical form that occurs following years after resolution of localized CL because of reactivation of the dormant parasites.1 In the Old World, LR is usually caused by Leishmania tropica, the main causative agent for CL in Turkey, an endemic country.2 The scarcity of the parasites in skin biopsy complicates the diagnosis, especially for patients in a nonendemic region. The lesions become destructive and disfiguring after many years because most of the patients may be resistant to regular treatment.1
The pathogenesis of LR is still unclear. Receiving incomplete course of treatment may play a role in resistance and recurrence of the lesions. The host immunologic status, especially defective Th1-type immune response, can also result in reduction of parasitic clearance.3
In our study covering 14-years and 8786 patients, we observed LR in 2,·29% of the pediatric CL patients, most commonly in 0 to 5-year-old group (4.34%). A more immature immune system relative to older children could explain this observation. This age group responded better than other groups to intralesional treatment, although follow-up observation is required because they were more prone to develop recidivans.2 Surprisingly, Sharifi et al1 reported more prevalent LR in the 6 to 10-year-old group.
We observed that the population in the refugee camps mostly consists of pediatric age groups. Thus, pediatric population is at risk of the diseases, indirectly LR.
In LR, the high rates resistant to the first line drugs necessitate new treatment alternatives. Successful results have been observed with combination therapies.4 Another recommended method is immunomodulatory therapy for LR.3 We suggest inducing the immune system to increase parasitic clearance or inhibiting the parasite-driven milieu which promotes parasite survival.
Our experience and some studies using thermotherapy, such as radiofrequency, thermotherapy and hand-held exothermic crystallization thermotherapy showed highly effective clinical cure rates in CL.5 Subsequently, a thermo-therapeutic approaching can overcome the treatment problem in LR cases because of thermo-sensitivities of the dermatotrophic L. tropica species.
Considerable progress has been made during the past decades to develop a vaccine against leishmaniasis. Depending on local epidemiologic data vaccine should be given priority for LR for children.
In conclusion, LR is an important clinical manifestation of CL with its higher morbidity, more duration to recover and more resistance to the standard therapy regimens. Local epidemiologic data should be considered in treatment decisions.