Original ArticlesHistologic diagnosis of cutaneous leishmaniasis
Section snippets
Histopathology of acute cutaneous leishmaniasis
Acute lesions of cutaneous leishmaniasis may present as papules, nodules, or plaques which are crusted or ulcerated (Fig 1). There is histologic similarity between the acute lesions of Old World leishmaniasis (oriental sore, Baghdad boil) and the New World lesions of acute leishmaniasis (uta, chiclero’s ulcer), with some differences seen in mucocutaneous leishmaniasis. Early in the course of disease, there is mixed inflammation (Fig 2).15 The inflammation is dense and diffuse throughout the
Histopathology of chronic cutaneous Leishmania
Some early authors differentiated Leishmania recidivans from chronic lupoid leishmaniasis, in that the former develops only after apparent healing of the primary lesion and is limited to its scar.22 Most authors, ourselves included, consider these entities to be identical.23 Single or sometimes multiple papular lesions develop at the edge of scars from previously healed acute lesions of leishmaniasis and progress gradually into an infiltrated scaly plaque which may show yellowish discoloration
Histopathology of disseminated cutaneous leishmaniasis
Disseminated cutaneous leishmaniasis (DCL) occurs in individuals with an anergic response to the Leishmania organism.27 This is most commonly caused by Leishmania aethiopica in the Old World and Leishmania mexicana amazonensis in the New World. Reports of DCL caused by Leishmania Venezuelensis have been reported from Venezuela.28 Clinically and histologically this form of leishmaniasis is similar to lepromatous leprosy. There is an infiltrate of monomorphous vacuolated appearing macrophages in
Histopathology of post Kala-Azar dermal leishmaniasis
Post Kala-Azar dermal leishmaniasis (PKDL) is most commonly secondary to visceral infection by Leishmania donovani. Lesions may appear from months up to 5 years after apparent successful treatment of visceral Kala-Azar. The clinical lesions may appear as hyperpigmented and hypopigmented macules, papules, and nodules. The hypopigmented macules show a decreased amount of epidermal pigment. The epidermis may be atrophic with keratotic follicular plugging.33 There may be a variable number of
Unusual presentations of cutaneous leishmaniasis
Several unusual and rare clinical presentations of cutaneous leishmaniasis have been described. Erysipeloid leishmaniasis has been described in Iranian women presenting clinically as erythematous indurative patches and plaques over the face and nose resembling erysipelas.35 Histologically, there are macrophages containing large numbers of amastigotes filling the upper dermis and extending into the deeper dermis along adnexal structures.35 A variable number of lymphocytes and plasma cells are
Histologic differential diagnosis of leishmaniasis
The differential diagnosis of acute cutaneous leishmaniasis includes other infectious granulomas. The histologic differential diagnosis would include sporotrichosis, blastomycosis histoplasmosis, yaws, syphilitic gumma, tuberculosis cutis, anthrax, granuloma inguinale, rhinoscleroma, and furunculosis. Identification of the organisms in the acute lesion should help to differentiate cutaneous leishmaniasis from these other infections. Rhinoscleroma, histoplasmosis, granuloma inguinale, and
Immunopathology of leishmaniasis
A great deal of work is underway concerning the immunopathology of many granulomatous processes. Much of this recent work is helpful in correlating the clinical and immunologic status of the patient to the histologic findings. For a more in-depth study, we encourage the reader to obtain the original references, however, we will attempt to summarize some of what is known and correlate this with the histologic findings.
The immunopathology of leishmaniasis is predominantly that of a T-cell
New techniques for diagnosis
Many new methods of diagnosis are available using immulogic and molecular biologic methods. Many of these methods are not commercially available yet, but may prove to be useful in the near future. Impression smear (touch preparations) of skin biopsy specimens has been shown to be an effective method for detecting organisms. Touch preps prepared by Giemsa stain have been shown to detect organisms in specimens which failed to show organisms by histologic examination.48 This is a relatively simple
Conclusions
The tropism of the infectious Leishmania organism, the size of the inoculum, and the underlying immune status of the patient will determine the clinical and histologic findings. The histopathology of cutaneous leishmaniasis is marked by a T-cell mediated immune response ranging from a mixed lymphohistologic infiltrate with many intracellular organisms in acute lesions to a well-defined epithelioid granuloma formation with few organisms in patients with chronic lesion and an intact immune
References (57)
American mucocutaneous leishmaniasis. Dermatol Clin
Contemporary Tropical Dermatol
(1994)- et al.
Clinical diagnosis of cutaneous leishmaniasis (Oriental sore)
J Am Acad Dermatol
(1987) - et al.
Leishmaniasis
J Am Acad Dermatol
(1996) - et al.
Histological spectrum of cutaneous leishmaniasis due to Leishmania Tropica
Tran R Soc Trop Med Hyg
(1985) - et al.
A new application of BCG antibody for rapid screening of various tissue microorganisms
J Am Acad Dermatol
(1998) The role of TH1 and TH2 cells in experimental cutaneous leishmaniasis
Exp Parasitol
(1989)- et al.
Murine cutaneous leishmaniasis susceptibility correlates with differential expansion of helper T-cell subsets
Ann Inst Pasteur Immunol
(1987) - et al.
Polymerase chain reactionBasic concepts and clinical applications in dermatology
J Am Acad Dermatol
(1994) Laboratory tests for the diagnosis and elevation of leishmaniasis
Dermatol Clin
(1994)Cutaneous leishmaniasis in TexasReport of a case and review of the literature
J Am Acad Dermatol
(1990)