Involvement of cell adhesion and activation molecules in the pathogenesis of erythema dyschromicum perstans (ashy dermatitis). The effect of clofazimine therapy.

OBJECTIVES: To assess the expression of several cell adhesion and lymphocyte activation molecules in erythema dyschromicum perstans lesions, and to evaluate the effect of clofazimine therapy on the expression of these molecules. DESIGN AND METHODS: A prospective study. Skin biopsy samples were obtained from patients before and after 3 months of clofazimine therapy, and the expression of cell adhesion and activation molecules was assessed by an immunohistochemical technique. SETTING: This study was performed in a clinical referral center and an immunology research laboratory. PATIENTS: We studied 6 patients with erythema dyschromicum perstans. A diagnosis was made on the basis of clinical and histological criteria. Two patients discontinued participation in the study: one because of adverse effects and the other for unknown reasons. INTERVENTIONS: Patients were treated with clofazimine, 100 mg/d, for 3 months. MAIN OUTCOME MEASURES: Expression of cell adhesion and lymphocyte activation molecules in skin biopsy specimens before and after clofazimine therapy. RESULTS: Before clofazimine therapy, we detected a noticeable expression of intercellular adhesion molecule 1 and major histocompatibility complex class II molecules (HLA-DR) in the keratinocyte basal cell layer. In addition, CD36, a thrombospondin receptor that is not expressed by normal skin, was detected in the strata spinosum and granulosum. The dermal cell infiltrate expressed the activation molecule AIM/CD69 and the cytotoxic cell marker CD94. After clofazimine therapy, the expression of intercellular adhesion molecule 1 and HLA-DR disappeared, as well as the mononuclear cell infiltrate. CONCLUSIONS: Our results suggest that some cell adhesion and activation molecules are involved in the pathogenesis of erythema dyschromicum perstans. Clofazimine appears to have an important effect on the inflammatory phenomenon of erythema dyschromicum perstans.

[Analysis of HLA-DR in Mexican patients with pemphigus]. / Análisis de HLA-DR en pacientes mexicanos con pénfigo.

UNLABELLED: Pemphigus are a group of bullous skin disorders histologically characterized by intraepidermal acantholytic and circulating antibodies blisters due to directed against the cellular surface of keratinocytes. In Mexican patients with pemphigus, HLA antigens have not been studied as they have been for other populations; for this reason, a comparative, prospective, transversal and observational study has been done with 25 patients, 18 with pemphigus vulgaris and the other seven with pemphigus foliaceus. DNA was extracted by the salting-out method and HLA-DR was determined by amplification with PCR and allele-specific oligonucleotides (ASO). RESULTS: HLA-DR14 (DR6) is more common in patients with pemphigus vulgaris than in the healthy population, which corroborates with previous reports. On the other hand, as reported we also found that HLA-DR1 in Mexican population represents a higher risk for pemphigus foliaceus.

Diffuse cutaneous mastocytosis with bone marrow infiltration in a child: a case report.

Mastocytosis encompasses a range of disorders characterized by overproliferation and accumulation of tissue mast cells. Mast cell disease is most commonly seen in the skin, but the skeleton, gastrointestinal tract, bone marrow, and central nervous system may also be involved. We present a 10-year-old boy with diffuse cutaneous mastocytosis characterized by disseminated papular, nodular, and infiltrated leathery lesions. The patient presented with chronic diarrhea and malnutrition. Laboratory studies were normal except for an elevated urinary 1-methylhistamine level. The bone marrow aspirate showed a dense mast cell infiltrate confirming systemic involvement.

Effectors of inflammation in actinic prurigo.

BACKGROUND: Actinic prurigo is a specific familial photodermatosis of uncertain pathogenesis. OBJECTIVE: Our purpose was to investigate the immunohistologic presentation of actinic prurigo to explore the involved pathomechanisms. METHODS: The present immunohistochemical study was performed on biopsy specimens from 20 Mexican patients presenting with a severe and perennial form of the disease. RESULTS: The dense inflammatory infiltrate was composed predominantly of helper T type 1 lymphocytes admixed with scattered B-cell lymphoid follicles and numerous dermal dendrocytes. Keratinocytes contained abundant tumor necrosis factor-alpha and calprotectin. CONCLUSION: In subjects genetically predisposed to actinic prurigo, ultraviolet light may trigger excessive tumor necrosis factor-alpha production by keratinocytes whose sustained release in turn exerts its proinflammatory activity and deleterious epidermal effects. Such a cascade of events is in line with the therapeutic benefit already reported when thalidomide is used to treat actinic prurigo.

Further evidence of the role of HLA-DR4 in the genetic susceptibility to actinic prurigo.

BACKGROUND: Actinic prurigo (AP) is triggered by sun exposure. Its prevalence in Mexicans seems to be particularly high, which suggests a genetic susceptibility. OBJECTIVE: Our purpose was to determine the role of major histocompatibility complex (MHC) genes in the genetic susceptibility to AP. METHODS: Fifty-six Mexican Mestizo patients with AP underwent serologic typing for HLA class I and class II antigens. Class II MHC genes were also studied by DNA analysis. Findings in patients were compared with 100 ethnically matched healthy controls. RESULTS: We found that 92.8% of patients with AP were HLA-DR4 positive (corrected p = 0.002; odds ratio [OR] = 10.1). The class I antigens HLA-A28 and HLA-B39 (B16) were also significantly increased (p < or = 0.000001, OR = 20.9 and p = 0.0001, OR = 6.7, respectively) compared with normal controls. Allele-specific oligonucleotide DR4 subtyping showed that 80.7% of HLA-DR4+ patients with AP were also positive for the DRB1*0407 allele. CONCLUSION: These results confirm the role of HLA-DR4 (DRB1*0407) in the genetic susceptibility to AP and raise the possibility of a role for class I MHC antigens HLA-A28 and B16 in Mexican patients.

Influence of nopal intake upon fasting glycemia in type II diabetics and healthy subjects.

To assess if the acute hypoglycemic effect of nopal which occurs in diabetic patients also appears in healthy individuals, 500 g of nopal stems (O. streptacantha Lem.) were given orally to 14 healthy volunteers and to 14 patients with NIDDM. Serum glucose and insulin levels were measured at 0, 60, 120 and 180 minutes after nopal ingestion. A control test was performed with the intake of 400 ml of water. The intake of nopal by the NIDDM group was followed by a significant reduction of serum glucose and insulin concentration reaching 40.8 + 4.6 mg/dl (n = 14) (mean+SEM) and 7.8 + 1.5 uU/ml (n = 7) less than basal value, respectively, at 180 minutes. (P less than 0.001 vs control test). No significant changes were noticed in the healthy group as compared with the control test (P greater than 0.05). Acute hypoglycemic effect of nopal was observed in patients with NIDDM but not in healthy subjects, thus the mechanisms of this effect differs from current hypoglycemic agents.

Lenticular acral keratosis in washerwomen.

BACKGROUND: In 1952, a Brazilian dermatologist, Oswaldo Costa, described a dermatosis characterized by accentuation of the cutaneous folds on the knuckles of both hands and small horny papules on the thenar eminences, posterior surface of the wrists, and the interdigital space between thumb and index finger; he called this entity acrokeratoelastoidosis. Other similar entities, such as focal acral hyperkeratosis and marginal keratoelastoidosis, have been described. The features of the different types of lenticular acral keratosis are discussed. MATERIALS AND METHODS: Fifteen patients with lenticular acral keratosis and five controls were studied clinically and pathologically. The skin biopsies were processed for light and transmission electron microscopy. The clinical data were reviewed, and the following variables were recorded: age, sex, distribution and morphology of the lesions, history of exposure to sunlight and objective evidence of photodamage, familial incidence, occupation and hobbies, time of evolution, and response to previous treatments. The results were compared with samples taken at autopsy from five women without dermatoses. RESULTS: All patients were women, with flat, keratotic papules located on the transition between the dorsal and volar surfaces of the fingers and hands. Histologically, there was an increased amount of elastic fibers, which were coarse and tortuous, and appeared to be interrupted in some areas. In contrast, there were sparse, thin fibers in the mid and deep dermis in the skin of controls. Transmission electron microscopy of these papules showed enlarged, thickened elastic fibers, with deposits of electron-dense, coarse clumps. CONCLUSIONS: Our cases do not seem to correspond to any of the three entities which are manifested clinically by acral keratotic plaques. All of these women washed clothes by hand on a stone washboard for many hours every day. As there is no clinical or histologic evidence of actinic damage, chronic trauma seems to be the cause of the dermatosis in this type of patient. We propose the term "occupational lenticular acral keratosis" for our cases.

Principales fotodermatosis en Latinoamérica: revisión y actualización / Photodermatosis present in Latinoamerica: review and actuallitation

Se exponen las características clínicas e histológicas y la terapéutica de las principales fotodermatosis presentes en América Latina. En esa extensa área se conjugan la existencia de grupos raciales peculiares a la región, alimentación y condiciones sociales particulares y elevada exposición solar. Algunas afecciones como el prurigo actínico tienen características propias y constituyen entidades nosológicas independientes