Sporotrichoid cutaneous leishmaniasis due to Leishmania major of different zymodemes in the Sudan and Saudi Arabia: a comparative study

Impetiginous Cutaneous Leishmaniasis after COVID-19 Infection in a Patient with Poor Cardiac Profile: A Case Report and Literature Review

Cutaneous leishmaniasis incidence has been rising in the past couple of decades. Standard therapy often includes antileishmanial drugs; however, due to their low safety and toxicity threshold, alternative treatments are being investigated. The association between COVID-19 and cutaneous leishmaniasis remains unclear and exploring this connection may offer crucial insights into the pathophysiology of and treatment strategies for infected patients. In this article, we describe a case of a male patient with a history of cardiac and other comorbidities who presented with cutaneous leishmaniasis in the form of impetigo-like skin lesions after being infected with COVID-19. Due to the patient's poor cardiac profile, sodium stibogluconate was not used and an alternative therapeutic approach was employed. The patient was treated with oral terbinafine, cryotherapy on specific lesions, and a course of cephalexin. Following the course of treatment and subsequent follow-up, the patient exhibited complete resolution and healing of the lesions with scarring, and no active lesions or recurrence were observed. This case highlights the potential for alternative treatment strategies for cutaneous leishmaniasis in patients with comorbidities and emphasizes the importance of further research to better understand the link between COVID-19 and cutaneous leishmaniasis.

Cutaneous sporotrichoid leishmaniasis: An atypical case caused by Leishmania major

A 32 year-old male was referred in our institution for painless erythematous papules on the back of the right hand, treated by various local therapies with no noticeable benefits. On examination multiples inconspicuous nodules were identified 10 days after the onset of the primary lesion. Mycological examination was done to rule out sporotrichosis, then cutaneous leishmaniasis was retained by finding amastigotes forms, and Leishmania major agent was confirmed after culture on NNN medium followed by isoenzyme electrophoresis. Sporortrichoid leishmaniasis is a rare condition and usually due to extension of local leishmaniasis into the subcutaneous tissue via direct extension, bloodstream or lymphatics. The patient responded favorably to Meglumine antimoniate treatment. To our knowledge, sporotrichoid cutaneous leishmaniasis after an erythematous-papular onset has never been reported in Algeria, this clinical entity should be considered for an earlier diagnosis and specific therapy.

Cutaneous leishmaniasis: A great imitator

Cutaneous leishmaniasis (CL) is called "the great imitator," because it can mimic almost all types of dermatoses. This similarity may sometimes lead to misdiagnosis, resulting in inappropriate treatment and morbidities. Atypical forms occur due to the interaction between parasitic factors and the host immune response. Secondary infection or mistreatment of CL can also alter the natural course, resulting in bizarre and misdiagnosed cases. Atypical leishmaniasis should be considered in longstanding and painless lesions that may simulate erysipelas, dermatitis, verruca, herpes zoster, paronychia, and sporotrichosis. Less commonly, sarcoidosis, deep mycosis, basal and squamous cell carcinoma, cutaneous lymphoma, or pseudolymphomalike lesions may need to be considered in the differential diagnosis. A high index of suspicion is required to consider a diagnosis of CL, especially in nonendemic or newly endemic regions. Smear, histopathologic examination, culture, and polymerase chain reaction serve as important tools to differentiate CL from its clinical and histologic look-alikes. CL is discussed from various perspectives, with emphasis on CL and its broad differential diagnosis.

Uncharted territory of the epidemiological burden of cutaneous leishmaniasis in sub-Saharan Africa-A systematic review

INTRODUCTION

Cutaneous leishmaniasis (CL) is the most frequent form of leishmaniasis, with 0.7 to 1.2 million cases per year globally. However, the burden of CL is poorly documented in some regions. We carried out this review to synthesize knowledge on the epidemiological burden of CL in sub-Saharan Africa.

METHODS

We systematically searched PubMed, CABI Global health, Africa Index Medicus databases for publications on CL and its burden. There were no restrictions on language/publication date. Case series with less than ten patients, species identification studies, reviews, non-human, and non-CL focused studies were excluded. Findings were extracted and described. The review was conducted following PRISMA guidelines; the protocol was registered in PROSPERO (42016036272).

RESULTS

From 289 identified records, 54 met eligibility criteria and were included in the synthesis. CL was reported from 13 of the 48 sub-Saharan African countries (3 eastern, nine western and one from southern Africa). More than half of the records (30/54; 56%) were from western Africa, notably Senegal, Burkina Faso and Mali. All studies were observational: 29 were descriptive case series (total 13,257 cases), and 24 followed a cross-sectional design. The majority (78%) of the studies were carried out before the year 2000. Forty-two studies mentioned the parasite species, but was either assumed or attributed on the historical account. Regional differences in clinical manifestations were reported. We found high variability across methodologies, leading to difficulties to compare or combine data. The prevalence in hospital settings among suspected cases ranged between 0.1 and 14.2%. At the community level, CL prevalence varied widely between studies. Outbreaks of thousands of cases occurred in Ethiopia, Ghana, and Sudan. Polymorphism of CL in HIV-infected people is a concern. Key information gaps in CL burden here include population-based CL prevalence/incidence, risk factors, and its socio-economic burden.

CONCLUSION

The evidence on CL epidemiology in sub-Saharan Africa is scanty. The CL frequency and severity are poorly identified. There is a need for population-based studies to define the CL burden better. Endemic countries should consider research and action to improve burden estimation and essential control measures including diagnosis and treatment capacity.

Cutaneous Leishmaniasis in Saudi Arabia: A Comprehensive Overview

Despite the great efforts by health authorities in Kingdom of Saudi Arabia (KSA), Cutaneous leishmaniasis (CL) continues to be a major public health problem in the country. Many risk factors make KSA prone to outbreaks and epidemics; among these, rapid urbanization and the huge population movement are the most important. The disease is endemic in many parts of KSA, with the majority of cases concentrated in six regions, including Al-Qaseem, Riyadh, Al-Hassa, Aseer, Ha'il, and Al-Madinah. Leishmania major (L. major) and Leishmania tropica (L. tropica) are the main dermotropic species, and Phlebotomus papatasi (vector of L. major) and Phlebotomus sergenti (vector of L. tropica) are the proved vectors of the disease. Psammomys obesus and Meriones libycus have been defined as the principal reservoir hosts of zoonotic CL in Al-Hassa oasis, Al-Madinah, and Al-Qaseem provinces. Clinically, males are affected more than females, and there is no variation between the Saudis and expatriates in terms of number of reported cases, but the disease tends to run a more severe course among non-Saudis. Face is the most commonly affected site, and ulcerative pattern accounts for 90% of lesions. Despite local and international recommendations of using laboratory diagnostics to confirm CL cases, most cases in KSA are diagnosed and treated on clinical grounds and local epidemiology. However, systemic parenteral sodium stibogluconate (SSG) is the first line of therapy and used to treat all CL patients irrespective of their clinical presentation or the incriminated species. In brief, more efforts are needed to combat this disease. Several aspects of the disease require more evaluation through encouragement of national and regional studies. Development of evidence based national diagnostic and management guidelines, as well as algorithms, is urgently needed to improve the practice of diagnosing and treating CL in KSA.

Rapid healing of cutaneous leishmaniasis by high-frequency electrocauterization and hydrogel wound care with or without DAC N-055: a randomized controlled phase IIa trial in Kabul

Background

Anthroponotic cutaneous leishmaniasis (CL) due to Leishmania (L.) tropica infection is a chronic, frequently disfiguring skin disease with limited therapeutic options. In endemic countries healing of ulcerative lesions is often delayed by bacterial and/or fungal infections. Here, we studied a novel therapeutic concept to prevent superinfections, accelerate wound closure, and improve the cosmetic outcome of ACL.

Methodology/Principal Findings

From 2004 to 2008 we performed a two-armed, randomized, double-blinded, phase IIa trial in Kabul, Afghanistan, with patients suffering from L. tropica CL. The skin lesions were treated with bipolar high-frequency electrocauterization (EC) followed by daily moist-wound-treatment (MWT) with polyacrylate hydrogel with (group I) or without (group II) pharmaceutical sodium chlorite (DAC N-055). Patients below age 5, with facial lesions, pregnancy, or serious comorbidities were excluded. The primary, photodocumented outcome was the time needed for complete lesion epithelialization. Biopsies for parasitological and (immuno)histopathological analyses were taken prior to EC (1^st), after wound closure (2^nd) and after 6 months (3^rd). The mean duration for complete wound closure was short and indifferent in group I (59 patients, 43.1 d) and II (54 patients, 42 d; p = 0.83). In patients with Leishmania-positive 2^nd biopsies DAC N-055 caused a more rapid wound epithelialization (37.2 d vs. 58.3 d; p = 0.08). Superinfections occurred in both groups at the same rate (8.8%). Except for one patient, reulcerations (10.2% in group I, 18.5% in group II; p = 0.158) were confined to cases with persistent high parasite loads after healing. In vitro, DAC N-055 showed a leishmanicidal effect on pro- and amastigotes.

Conclusions/Significance

Compared to previous results with intralesional antimony injections, the EC plus MWT protocol led to more rapid wound closure. The tentatively lower rate of relapses and the acceleration of wound closure in a subgroup of patients with parasite persistence warrant future studies on the activity of DAC N-055.

Trial Registration

ClinicalTrails.gov NCT00947362

In many countries of the Middle East such as Afghanistan, cutaneous leishmaniasis is a highly prevalent, chronic and stigmatizing skin disease. Poor hygiene conditions frequently aggravate the lesions due to bacterial and fungal superinfections. Classical treatments with injections of pentavalent antimony are hampered by costs, side effects, resistance development, supply and manufactural quality problems. In the present study on Afghan patients with Leishmania tropica-induced skin lesions we evaluated the clinical effect of an initial removal of lesion tissue by electrocoagulation using a bipolar high-frequency electrosurgery instrument, followed by daily moist wound treatment with or without a preparation of pharmaceutical sodium chlorite (DAC N-055). DAC N-055 is a compound with anti-infective, immunomodulatory and tissue repair-promoting effects. Our analysis revealed that the carefully performed moist wound treatment led to a rapid healing of the wounds within an average period of 6 weeks, even in the absence of the sodium chlorite preparation. This is considerably faster than the time spans previously reported for local or systemic antimony treatment. We believe that the current standard for local care of chronic wounds should also be applied to Leishmania skin lesions. If combined with an initial single high-frequency electrocoagulation, it is a highly effective, inexpensive and well-tolerated treatment option for cutaneous leishmaniasis.

Cutaneous leishmaniasis (Leishmania major infection) in Dutch troops deployed in northern Afghanistan: epidemiology, clinical aspects, and treatment

Cutaneous leishmaniasis caused by Leishmania major infection affected 172 (18.3%) of 938 Dutch military troops deployed in northern Afghanistan in 2005. The high attack rate was a result of initial insufficient availability of means of prevention and insufficient adherence to preventive measures. At presentation, the lymphatic system was involved in 24.8%. Treatment with intralesional injections of antimony with or without cryotherapy was satisfactory, but 19.5% of patients received secondary treatment with miltefosine. Six months after treatment, 128 (77.1%) of 166 treated patients were cured, 16 (9.6%) were lost to follow-up, and 22 (13.3%) already experienced cure at six weeks but were not seen at six months. Natural evolution played a role in this observational study, which showed cure of all patients seen at six months. In general, management of cutaneous leishmaniasis was feasible under field conditions.

[Sporotrichoid cutaneous leishmaniasis in Tunisia: a clinical and histological study]

BACKGROUND

The sporotrichoid variety of cutaneous leishmaniasis is defined by the presence of dermal and hypodermal nodules along the lymphatic stream, and remote from the primary inoculation lesions. This clinical form is usually considered rare. The aim of our study was to investigate the epidemiological, clinical, histological and evolutionary particularities of sporotrichoid cutaneous leishmaniasis in the south of Tunisia.

PATIENTS AND METHODS

During a systematic study of all cases of cutaneous leishmaniasis from the south of Tunisia diagnosed in our hospital in 2002, sporotrichoid forms were diagnosed on the basis of clinical criteria. In all cases of sporotrichoid cutaneous leishmaniasis, the principal clinical characters were systematically specified. Cutaneous biopsies of subcutaneous nodules were performed in six cases.

RESULTS

Of 102 patients with cutaneous leishmaniasis, 19 presented sporotrichoid cutaneous leishmaniasis, that is, a frequency of 19%. Between two and 20 painless subcutaneous nodules were arranged in linear strings on the upper leg in 79% of cases. Time to appearance varied between 12 days and one year after the primary lesions. Fourteen appeared without any preliminary treatment for cutaneous leishmaniasis and five appeared after Glucantime infiltration in the primary lesions. Biopsies of the nodules showed an inflammatory infiltrate composed of lymphocytes and histiocytes. This infiltrate was particularly dense and rich in plasmocytes at the level of the deep dermis. The biopsies were deep enough to involve the hypoderm in one case and the same type of infiltrate was noted at the level of interlobular septa. A small number amastigotes was seen in one deep biopsy sample. Outcome was favourable in all cases under treatment.

CONCLUSION

Sporotrichoid cutaneous leishmaniasis appears to be common in the south of Tunisia, were cutaneous leishmaniasis is dominant because of Leishmania major. It is not associated with a poor prognosis.

Cutaneous leishmaniasis

Cutaneous leishmaniasis is a widespread tropical infection caused by numerous different species of Leishmania protozoa that are transmitted by sandflies. Its clinical presentations are extremely diverse and dependent on a variety of parasite and host factors that are poorly understood. Diagnosis should aim to identify the exact species involved, but this requires laboratory investigations that are not widely available. No single ideal treatment has been identified, and those available are limited by variable success rates and toxicity. Clinical guidelines are needed to make better use of the investigations and treatments that do exist. Prevention is currently limited to bite prevention measures.

Uncommon clinical presentations of cutaneous leishmaniasis in Sudan

Cutaneous leishmaniasis in Sudan is caused by Leishmania major zymodeme LON1. Self-healing usually occurs within 1 year but occasionally its duration is prolonged and treatment is required. The clinical forms are ulcers, nodules and noduloulcerative lesions. Here we describe seven patients with uncommon lesions that were difficult to recognize as Leishmania infections. These included mycetoma-like lesions, lesions that resembled L. tropica infection and others. One HIV/AIDS patient had Kaposi's sarcoma with Leishmania parasites in the Kaposi lesions. Most of these uncommon clinical forms were difficult to treat. The diagnosis depended on a high degree of suspicion and the demonstration of parasites in smears or culture. PCR was used to characterize parasites from the patients described here. Leishmania major was found by kDNA PCR in all patients, except one, who had a leishmanioma due to L. donovani. In three patients, including one with a L. tropica like-lesion, the parasites were confirmed as L. major by gp63 PCR-RFLP.

Clinical and histopathological features of zoonotic cutaneous leishmaniasis in Saudi Arabia

BACKGROUND

Zoonotic cutaneous leishmaniasis (ZCL) caused by Leishmania major is a growing public health problem and endemic in many parts of the Kingdom of Saudi Arabia. The vector is Phlebotomus papatasi and the animal reservoirs are mainly desert rodents.

METHODS

In this prospective study, the clinical and histopathological features of ZCL in 120 patients are described and classified. The majority of these patients (n = 84) were non-Saudi expatriate workers who suffered mostly from multiple and severely inflamed nodulo-ulcerative lesions on the exposed parts of the body. Saudi patients were mainly children (n = 21) with few(1-3) lesions on their limbs or sometimes unique erysipeloid facial lesions.

RESULTS

Histopathological grouping of ZCL lesions showed four types of granulomatous reactions based on the predominant types of inflammatory cells, presence or absence of necrosis and ranking of parasitic index.

CONCLUSION

A possible correlation between histopathologic evolution of ZCL lesions and the immune status of the host is discussed.

Cutaneous leishmaniasis in the returning traveler

Infection with protozoan parasites of the genus Leishmania leads to a wide variety of clinical disease syndromes called leishmaniasis, or more appropriately the leishmaniases. The three major clinical syndromes are cutaneous leishmaniasis, mucosal leishmaniasis, and visceral leishmaniasis. All three of these syndromes have been documented in returning travelers. This article focuses on cutaneous leishmaniasis with some comment on mucosal leishmaniasis.

1. Cutaneous leishmaniasis

Cutaneous leishmaniasis (CL) in Sudan is caused by Leishmania major, zymodeme LON-1. The disease is endemic in many parts of the country. The vector is Phlebotomus papatasi and the animal reservoir is probably the Nile rat Arvicanthis niloticus. Clinically, patients usually present with papules, nodules, or nodulo-ulcerative lesions, mainly on the exposed parts of the skin. In 20% of cases the parasite disseminates through the lymphatics, producing sporotrichoid-like lesions. The pathology of the lesion is described. Langerhans cells are the main antigen-presenting cells in CL. They pickup antigen from the dermis and migrate to regional lymph nodes where they present it to T cells. Antigen-specific activated T cells home to the dermis where they stimulate macrophages to eliminate the parasite. Peripheral blood mononuclear cells (PBMC) proliferate in response to Leishmania antigen in vitro and produce cytokines. PBMC of patients with mild and severe disease produce Th1- and Th2-like cytokine patterns, respectively. The criteria for the clinical diagnosis of CL are described. The diagnosis is confirmed by the demonstration of parasites in slit smears in 50-70% of cases and in histological sections in 70%. With primers specific for L. major, the polymerase chain reaction is positive in 86% of cases. Since CL is a self-limiting disease, treatment is confined to patients with severe disease.

4. Post kala-azar dermal leishmaniasis

Post kala-azar dermal leishmaniasis (PKDL) is increasingly recognized in Sudan as a complication of visceral leishmaniasis (VL), occurring in c. 55% of patients after, or during treatment of, VL. The development of PKDL seems to be restricted to parasites of the Leishmania donovani sensu stricto cluster; no particular zymodeme has been found to be associated with it. In contrast to PKDL in India, PKDL in Sudan occurs within 0-6 months after treatment for VL. The rash may be macular, maculo-papular or nodular, and spreads from the perioral area to other parts of the body, depending on grade of severity. Young children are particularly at risk of developing more severe disease. In 16% of PKDL patients, parasites can be demonstrated by microscopy in lymph node or bone marrow aspirates and, with the aid of the polymerase chain reaction (PCR), in lymph nodes of 81% of patients, possibly indicating persistent visceralized infection. Diagnosis can be made by demonstration of parasites in skin smears or biopsies in 20-30% of cases; newer techniques, using PCR with skin smears, have higher sensitivity (83%). Monoclonal antibodies against L. donovani can detect parasites in 88% of biopsies. Serological tests are of limited value. The leishmanin skin test is positive in 50-60% of cases; there is an inverse relationship between the skin test result and severity of PKDL. In differential diagnosis, miliaria rubra is the most common problem; differentiation from leprosy is the most difficult. In biopsies, hyperkeratosis, parakeratosis, acanthosis, follicular plugging and liquefaction degeneration of the basal layer may be found in the epidermis; in the dermis there are varying intensities of inflammation with scanty parasites and mainly lymphocytes; macrophages and epithelioid cells may also be found. In 20% of cases discrete granulomas may be found. After VL, the immune response shifts from a Th2-type to a mixed Th1/Th2-type. High levels of interleukin-10 in skin biopsies as well as in peripheral blood mononuclear cells and plasma in patients with VL predict the development of PKDL. Treatment is needed only for those who have severe and prolonged disease; sodium stibogluconate (20 mg/kg/d for 2 months) is usually sufficient. (Liposomal) amphotericin B is effective, whereas ketoconazole, terbinafine and itraconazole are not.

Dissemination in cutaneous leishmaniasis due to Leishmania major in different ethnic groups in Saudi Arabia

BACKGROUND

Dissemination in patients with cutaneous leishmaniasis has previously been recorded in human infection with Leishmania major and L. tropica. In this study, the potential for dissemination in different ethnic groups in Saudi Arabia was compared.

METHODS

The data were recorded from a group of 73 patients with suspected cutaneous leishmaniasis (43 Saudi and 30 non-Saudi) attending the Dermatology Clinics at King Fahd Hospital of the University and Al-Khobar Government Hospital at Al-Khobar, Eastern Region of Saudi Arabia. The patients were of various age groups (all male) between 1 and 55 years. The diagnosis of cutaneous leishmaniasis was confirmed clinically and by smear and skin biopsy. The following data were recorded for each patient: type, number, and anatomic sites of disseminative lesions and the frequency of co-occurrence of more than one type of lesion.

RESULTS

Three types of disseminative lesions due to zoonotic cutaneous leishmaniasis were recorded in 16 patients (21.92%): subcutaneous nodules, satellite papules, and subcutaneous induration. The percentage of disseminative lesions in non-Saudi patients (36.66%) was higher than in Saudi patients (11. 63%). This was also true for the number of lesions: a mean of 12.27+/- 10 and 6.4+/-3, respectively. The coexistence of more than one type of disseminative lesion was higher in non-Saudi patients (63. 63%) than in Saudi patients (20.0%), as well as the occurrence of lesions on more than one body site: 36.4% in non-Saudi patients and 20.0% in Saudi patients.

CONCLUSIONS

The potential for dissemination due to cutaneous leishmaniasis was significantly higher in the nonindigenous population than in the indigenous population in Saudi Arabia. Disseminative lesions must be clinically differentiated from other skin diseases and appropriately treated by avoiding the use of intralesional drugs or physical therapy.

Cutaneous New World leishmaniasis-sporotrichosis coinfection: report of 3 cases

Three cases of coinfection with Leishmania and Sporothrix spp in the same lesion are described. The patients had ulcers with erythematous borders and regional lymphadenopathy. The diagnosis of leishmaniasis was accomplished by direct visualization of the amastigotes or culture of the promastigotes, or both. The diagnosis of sporotrichosis was proved in two cases by culture of Sporothrix schenckii and by the histopathologic features in one case. All patients had a positive sporotrichin test. Two patients responded successfully to oral potassium iodide. One patient received oral itraconazole 100 mg/day because of intolerance to iodides and was cured. To our knowledge coinfection with Leishmania and Sporothrix spp has not been reported. The use of empirical treatments for leishmaniasis such as poultices or puncturing of the lesion with thorns or woods splinters might introduce Sporothrix and explain the coinfection.

Characterization of the local and systemic immune responses in patients with cutaneous leishmaniasis due to Leishmania major

In this study skin biopsies and peripheral blood samples were obtained from patients with cutaneous leishmaniasis caused by Leishmania major. Samples were obtained at diagnosis and during healing when the lesions had regressed to half the original size. At diagnosis most of the cells expressed HLA-DR. The numbers of CD8+ cells in the lesions were higher at diagnosis than during healing. By contrast, a lower percentage of PBMC expressed CD8+ cells at diagnosis probably due to sequestration in the lesion. In the lesion, in situ staining for IFN-gamma, IL-10, and IL-4 showed marked variation between all patients in the number of positive cells for a particular cytokine. The proliferative response of PBMC to leishmanial antigens and IFN-gamma production tended to increase during healing. Cytokine patterns in the PBMC in response to Leishmania antigen was more specific than in the lesion and correlated better with the clinical manifestations. Possible reasons for this are discussed.

Lymphocutaneous syndrome. A review of non-sporothrix causes

The lymphocutaneous syndrome can be caused by a number of diverse microorganisms requiring very different antimicrobial therapy for resolution. The epidemiology and geographic occurrence of the infection often can provide important first clues to the microbiologic etiology. Accurate diagnosis can be accomplished usually by punch or wedge biopsy of a primary lesion or proximal subcutaneous nodule submitted for histopathologic examination and culture. The microbiology laboratory staff should be alerted to the diagnostic possibilities so that appropriate cultural and incubation techniques, procedures, and precautions can be initiated. Provision of a correct microbiologic diagnosis and institution of appropriate antimicrobial therapy will result in a complete cure in almost all instances. Adjunctive surgical debridement may be required for certain organisms such as Nocardia or Mycobacterium chelonae.

Multiple lesions of sporotrichoid leishmaniasis in a Filipino expatriate

Sporotrichoid cutaneous leishmaniasis (CL) was diagnosed in a Filipino man who had worked in Saudi Arabia for 2 years. Two primary lesions-one on the forearm and one on the abdomen-were characterized by "satellite" papules and subcutaneous nodules extending proximally in a sporotrichoid pattern. Leishmania organisms were found in both primary lesions and a subcutaneous nodule. There was no evidence of systemic involvement. Recognition that Old World CL may disseminate through lymphatic channels has diagnostic and therapeutic importance.

Necrotizing and suppurative lymphadenitis in Leishmania major infections

The pathology of lymph nodes and subcutaneous nodules in 6 patients with cutaneous leishmaniasis (Oriental sore) due to Leishmania major is described in this paper. In 3 patients enlarged epitrochlear lymph nodes were found to be associated with primary skin lesions in the forearm. The lymph node in one patient showed a necrotizing granulomatous reaction that simulated tuberculous lymphadenitis. Leishmania parasites were, however, found in sections of the node, and staining for mycobacteria was negative. The second patient presented with an abscess and a discharging sinus in the epitrochlear region. Parasites were found in smears of the pus and cultures for bacteria were negative. The lesion healed with antimonial therapy. In the third patient the lesion resembled cat-scratch disease and showed stellate abscesses and granulomas. Leishmania parasites were also identified in the sections. Sections of a subcutaneous nodule from the fourth patient showed a necrotizing granuloma. The lesion healed spontaneously and the patient became leishmanin-positive. In two other patients fine needle aspiration of the subcutaneous nodules showed parasites, granuloma and necrosis. We concluded that L. major disseminates from the primary cutaneous lesion via the lymphatics to the subcutaneous tissues and the regional lymph nodes. The subcutaneous nodules and lymphadenopathy may persist long after the primary lesion had healed. The primary lesion is sometimes inconspicuous. Necrotizing and suppurative lymphadenitis due to L. major have to be distinguished from other causes of necrosis and suppuration such as tuberculosis and cat-scratch disease.

Antigen-presenting cells in human cutaneous leishmaniasis due to Leishmania major

In this study biopsies from skin lesions and draining lymph nodes of patients suffering from cutaneous leishmaniasis caused by Leishmania major were examined by immunohistochemistry, and by light and electron microscopy to identify the types of antigen-presenting cells (APC) and their location. APC, identified morphologically and by their expression of specific cell markers, included Langerhans cells, macrophages, follicular dendritic cells, and interdigitating reticulum cells of the paracortex of lymph nodes. These cells expressed MHC class II antigens and contained Leishmania antigen. Since some keratinocytes and endothelial cells also showed these characteristics, they may also act as APC. By examining tissue samples from skin lesions and draining lymph nodes it was possible to follow the probable route of trafficking of various inflammatory cells between the skin lesion and lymph nodes. Leishmania antigen containing Langerhans cells were found in the epidermis, dermis and the regional lymph nodes. We believe these cells translocate from the epidermis to the dermis, where they take up antigen and migrate to the paracortex of the regional lymph nodes. There they are intimately associated with cells of the paracortex, and could be involved in the generation of Leishmania-specific T memory cells. LFA-1-positive T cells of the CD45RO phenotype were found in the skin lesion. Venular endothelium in the skin lesions expressed intercellular adhesion molecule-1 (ICAM-1), which is the ligand for LFA-1. The migration of lymphocytes from the vascular lumen to the site of inflammation is possibly a result of the interaction of these two adhesion molecules.