[Importance of dermatopathology in the diagnosis of tropical and travel-associated skin diseases]. / Bedeutung der Dermatohistologie in der tropen- und reisedermatologischen Diagnostik.

BACKGROUND: Skin diseases are frequent in tropical countries and cause a significant burden for their health systems. Tropical dermatoses are frequently of infectious nature. DIAGNOSTICS: Dermatopathology plays an important role in the diagnosis of many tropical skin diseases. This refers specially to leishmaniasis, tropical helminthic diseases, tuberculosis, leprosy, and deep fungal infections. In addition, dermatopathology is important for the differential diagnosis of non-infectious inflammatory diseases in pigmented skin; their identification may be more challenging than when seen in Caucasian skin. CONCLUSION: While it is usually not problematic to perform a dermatopathologic workup in travelers and expatriates returning from the tropics into Western industrialized countries, dermatopathologic services are frequently non-existent or severely limited in many tropical countries. Therefore, in improving health systems, not only should a dermatologic workforce be developed, but also training of dermatopathologists and the establishment of dermatopathology laboratories should be considered.

[Inflammatory dermatoses]. / Entzündliche Dermatitiden.

The seven basic patterns of inflammatory dermatoses according to Ackerman can be applied to infectious dermatoses. However, it should be borne in mind that infection caused by one agent may induce differing patterns according to the stage of disease. Dermatophytosis and the arthropod reaction belong to perivascular dermatoses with spongiosis. Secondary syphilis and acrodermatitis chronica atrophicans regularly show a lichenoid infiltrate with interface dermatitis, whereas epidermal involvement is typically absent in erythema migrans, virus exanthema and bacillary angiomatosis. Lupus vulgaris, atypic mycobacteriosis, lepra, actinomycosis, cutaneous leishmaniosis and erysipelas belong to the nodular and diffuse dermatoses. In the group of vasculitides, septic vasculitis is induced by a biological agent, and the pattern of vesicular dermatitis is reflected by infections with herpes viruses, impetigo contagiosa and staphylococcal scalded-skin syndrome. Follicular dermatitis shows a pattern of furuncles and carbuncles which are mainly caused by bacteria or fungi.

Immunophenotype of skin lymphocytic infiltrate in patients co-infected with Mycobacterium leprae and human immunodeficiency virus: a scenario dependent on CD8+ and/or CD20+ cells.

BACKGROUND: Leprosy occurs rarely in human immunodeficiency virus (HIV)-positive patients. In contrast to tuberculosis, there has been no report to date of an increase in HIV prevalence among patients with leprosy or of differences in leprosy's clinical spectrum. While several studies describe the systemic immune response profile in patients co-infected with HIV and leprosy, the local immune skin response has been evaluated in only a small number of case reports and limited series of patients. OBJECTIVE: To investigate the interaction between Mycobacterium leprae and HIV infection in the skin. METHODS: We investigated the presence and frequency of cells positive for CD4, CD8, CD20, TIA-1, FOXP3 and CD123 in lymphocytic infiltrates from 16 skin biopsies taken from 15 patients with HIV-leprosy co-infection. RESULTS: CD4+ cells were absent in infiltrates from 6 (38%) skin biopsies and present in 10 (62%) cases at low levels (<1·16%) of the lymphocytic infiltrate. CD8+ was the predominant phenotype in the infiltrate (99·4%), followed by TIA-1, expressed by >75% of CD8+ cells. FOXP3+ cells were also present, representing 3·4% of the lymphocytic infiltrate. CD20+ cells were detected in 75% of the cases; however, in two cases (12%) these cells represented 25-50% of the infiltrate, while in the other 10 cases (62%) they were present only focally (<25% of the infiltrate). CD123+ cells were not observed in any of the studied specimens. CONCLUSIONS: Data presented here suggest that cell-mediated immune responses to M. leprae are preserved at the site of disease and that in the absence of CD4+ cells, CD8+FOXP3+ and CD20+ cells may be involved in granuloma formation.

Arcuate, annular, and polycyclic inflammatory and infectious lesions.

Common shapes encountered in dermatologic diseases include linear, nummular, annular, polycyclic, and arciform. The last three have a relatively restricted differential, which must be entirely explored. It is not uncommon for a single disease to present in annular, arciform or polycyclic configurations; moreover, the lesions may evolve from being arciform to annular and then become polycyclic. Regardless, recognizing the arrangement of the defect will undoubtedly help in making a diagnosis and guiding subsequent management. We explore diseases that often present in annular, arciform, and/or polycyclic forms.

Disseminated cutaneous rhinosporidiosis: varied morphological appearances on the skin.

Rhinosporidiosis is a chronic granulomatous disorder caused by Rhinosporidium seeberi . It frequently involves the nasopharynx and occasionally affects the skin. We report a case of 45-year-old man who had disseminated cutaneous rhinosporidiosis with cutaneous pseudohorn, its base arising from rhinosporidiosis. The case presented with multiple reddish lesions over the nose of six years duration. In the past year, he developed skin lesions over the left arm, forearm, back, and chest. On examination, polymorphic lesions of rhinosporidiosis in form of verrucous plaque, unulcerated tumor, granulomatous growth, and furunculoid lesions were observed. Interestingly, there was a cutaneous horn over the chest which on histopathological examination showed hyperplastic epithelium with numerous globular cysts of varying shape, representing sporangia in different stages of development and transelimination. Computerized tomography scan of the chest showed bilateral opacities suggestive of lung involvement. On the basis of these clinical and histopathological findings, a diagnosis of nasal rhinosporidiosis with cutaneous and systemic dissemination was made.

Palsy of the rear limbs in Mycobacterium lepraemurium-infected mice results from bone damage and not from nerve involvement.

A small but relatively constant proportion (3-5%) of mice chronically infected with Mycobacterium lepraemurium (MLM) develops bilateral paralysis of the rear limbs. The aim of the study was to investigate whether or not the bilateral leg palsy results from nerve involvement. Direct bacterial nerve infection or acute/delayed inflammation might possibly affect the nerves. Therefore, palsied animals were investigated for the presence of: (a) histopathological changes in the leg tissues including nerves, bones and annexes, and (b) serum antibodies to M. lepraemurium and M. leprae lipids, including phenolic glycolipid I from M. leprae. Histopathological study of the palsied legs revealed that the paralysis was not the result of direct involvement of the limb nerves, as neither bacilli nor inflammatory cells were observed in the nerve branches studied. Antibodies to brain lipids and cardiolipin were not detected in the serum of the palsied animals, thus ruling out an immune response to self-lipids as the basis for the paralysis. Although high levels of antibodies to MLM lipids were detected in the serum of palsied animals they were not related to limb paralysis, as the nerves of the palsied legs showed no evidence of inflammatory damage. In fact, nerves showed no evidence of damage. Paralysis resulted from severe damage of the leg bones. Within the bones the bone marrow became replaced by extended bacilli-laden granulomas that frequently eroded the bone wall, altering the normal architecture of the bone and its annexes, namely muscle, tendons and connective tissue. Although this study rules out definitively the infectious or inflammatory damage of nerves in murine leprosy, it opens a new avenue of research into the factors that participate in the involvement or the sparing of nerves in human and murine leprosy, respectively.

Incapacidades físicas em pacientes de hanseníase na faixa de zero a 14 anos, no Distrito Federal, no período de 1979 a 1989 / Physical disabilites in leprosy patients in the ) to 14 age group, in the Federal District, between the years 1979 and 1989

Um estudo retrospectivo foi realizado em relaçäo à ocorrência de incapacidades físicas em 148 pacientes portadores de hanseníase, na faixa etária de zero a 14 anos, no Distrito Federal, no período compreendido entre 1979 e 1989. Procurou-se correlacionar as incapacidades com a idade, sexo, localizaçäo e formas clínicas da doença. A taxa de incapacidades foi de 11,49%. A faixa etária mais acometida por incapacidades foi a de 11 a 14 anos, com percentual de 82,35%. Houve predomínio em crianças do sexo masculino (58,82%). As mäos foram os locais mais acometidos pelas incapacidades, com 71,42%. Houve correlaçäo entre as formas clínicas da doença e a taxa de incapacidades físicas, indicando as formas multibacilares com destaque para a forma dimorfa como as que mais incapacitam

Dermatopathologic findings in patients infected with HIV.

Several inflammatory, infectious, and neoplastic conditions in HIV-infected patients are distinctive or require a biopsy for diagnosis. Some differ subtly from similar conditions seen in noninfected patients. The exanthem of acute HIV infection cannot be diagnosed specifically on biopsy as its histologic appearance is similar to that of other viral exanthemata. A condition that closely resembles seborrheic dermatitis occurs in HIV-infected patients. Plasma cells, necrotic keratinocytes, and leukocytoclasis may be present, in contrast to findings in sporadic seborrheic dermatitis. Psoriasis and Reiter's disease also occur in HIV-infected patients and can be specifically diagnosed as such. The category "psoriasiform dermatitis of AIDS" thus seems to include several distinct entities and not to be a single disease. Bacillary angiomatosis is a treatable infection caused by a rickettsialike organism similar to Rochalimaea quintana, the agent of trench fever. Cutaneous lesions are characterized by lobules of capillaries with protuberant endothelial cells, neutrophils and their debris, and purplish-staining clumps of organisms, which can be demonstrated with silver stains or electron microscopy. An unusual reaction to atypical mycobacterial infection, in which spindle-shaped macrophages are seen, resembles histoid leprosy. Viral skin diseases that may challenge the dermatopathologist include unusual verrucous reactions to chronic varicella-zoster infection and flat warts caused by the human papillomavirus associated with epidermodysplasia verruciformis. Keratinocytes with foamy basophilic cytoplasm may be a marker for one of these viruses, human papillomavirus type 5. Neoplastic complications of HIV disease include Kaposi's sarcoma and mycosis fungoides. The earliest lesions of the patch stage of Kaposi's sarcoma show a slightly increased number of cells with small ovoid nuclei around preexistent structures, accompanied, in some cases, by sparse infiltrates of lymphocytes and plasma cells. Staining with antisera to type IV collagen may highlight the vascular spaces in these early lesions. Later lesions that resemble hemangiomas may also prove challenging and require level sections to demonstrate the presence of spindle cells and eosinophilic globules. Although HIV is cytotoxic to helper T cells, neoplastic proliferations of them may be seen in HIV-infected patients. These cases of mycosis fungoides do not seem to differ from sporadically occurring ones and occur in patients who seem not to be infected by HTLV-I.

The pathology of Mycobacterium ulcerans infection.

The pathology of cutaneous ulcers resulting from Mycobacterium ulcerans infection is reviewed. Initial infection causes ulceration with necrosis of the dermis and a septate panniculitis in subcutaneous fat. There is little cellular reaction despite the presence of large numbers of organisms. Recurrent or persistent infection produces a granulomatous reaction with epithelioid macrophages, variable numbers of giant cells of the Langhans type, and relatively few organisms. This type of reaction is associated with more successful treatment of the disease and appears analogous to the tuberculoid form of leprosy.

The cutaneous infiltrates of leprosy. A transmission electron microscopy study.

The dermal lesions of 18 patients with leprosy have been examined by transmission electron microscopy. The patients exhibited a spectrum of disease from polar lepromatous to polar tuberculoid with intermediate stages in various states of therapy and relapse. The nature and quantities of inflammatory cells and bacteria have been determined by electron microscopy to supplement previous light and fluorescence microscopy studies. Lepromatous leprosy was characterized by many parasitized foam cells containing large, multibacillary vacuoles with intact, osmiophilic Mycobacterium leprae: Bacteria were embedded in an electron-lucent matrix. No extracellular bacteria were evident. Only small numbers of scattered lymphocytes were found. As one approached the borderline state, smaller numbers of bacilli were present as singlets and doublets in small vacuoles of macrophages. The more reactive forms showed increasing bacillary fragmentation, larger numbers of lymphoid cells, and an occasional epithelioid cell. At the tuberculoid end of the spectrum, clear evidence of an exuberant lymphocyte response was evident. Large numbers of T cells with extremely long and complex filipodia were closely associated with epithelioid and multinucleated giant cells. Many of the mononuclear phagocytes appeared nonviable, and areas of necrosis were evident. Bacillary remnants were scarce and the cytoplasm of the epithelioid cells contained occasional dense bodies and many stacks of endoplasmic reticulum and mitochondria. These results suggest that Leu 3a/OKT4 helper cells may be capable of driving the effector function of mononuclear phagocytes. This would lead to a significant microbicidal effect on M. leprae, perhaps through the production of toxic oxygen intermediates.

Experimental transmission of a feline mycobacterial skin disease (feline leprosy).

Non-culturable acid-fast bacteria from two spontaneous cases of so-called feline leprosy were transmitted to rats and cats and further passaged in rats or cats. Two to six months after infection, cats developed cutaneous lesions that were indistinguishable from spontaneous cases, including the occurrence of nasal granulomata in one cat. When injected into rats, the mycobacteria caused a generalized mycobacteriosis and the granulomatous reaction was composed chiefly of macrophages without polymorphonuclear granulocytes. Infection of cats with Mycobacterium lepraemurium did not produce any lesions. The feline disease may be a suitable model for the study of human leprosy (Hansen's Disease).