Value of diagnostic techniques for cutaneous leishmaniasis.
BACKGROUND
Traditional diagnostic tests, ie, smear, culture, and histopathology of a skin biopsy specimen, are not always conclusive in patients with a clinical diagnosis of cutaneous leishmaniasis (CL).


OBJECTIVE
Our purpose was to find out if a polymerase chain reaction (PCR) specific for Leishmania organisms might be more sensitive than the traditional diagnostic techniques, thereby decreasing the number of false-negative diagnoses.


METHODS
In a prospective study, smear, culture, and histopathology of skin biopsy specimens from 46 patients with a possible diagnosis of CL were compared with PCR specific for Leishmania. In addition, the Montenegro test as a measure of cellular immunity against the Leishmania parasite was performed. Proven CL was defined as a case in which at least 1 of the 3 traditional tests showed the presence of Leishmania parasites.


RESULTS
Of our 46 patients, 22 had leishmaniasis. Of the traditional tests, culture was the most sensitive but there were no statistically significant differences between the sensitivities of the various tests. PCR results were positive in all cases of proven leishmaniasis. Moreover, 3 patients with the clinical diagnosis of CL and negative findings on traditional tests had positive PCR results. Only 1 patient with a strong clinical suggestion of CL and positive Montenegro test results had negative PCR findings; this patient also had negative smear, culture, and histopathology results.


CONCLUSIONS
PCR appears to be the most sensitive single diagnostic test for CL.
Faber
William R
WR
Department of Tropical Dermatology, Academic Medical Center, The Netherlands.
Oskam
Linda
L
van Gool
Tom
T
Kroon
Nel C M
NC
Knegt-Junk
Kristine J
KJ
Hofwegen
Henk
H
van der Wal
Allard C
AC
Kager
Piet A
PA
D006801:Humans; D016773:Leishmaniasis, Cutaneous / Q000175:diagnosis*; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D012882:Skin Tests; D013048:Specimen Handling