María Elisa Vega-Memije

Giant onychomatricoma: report of two cases with rare clinical presentation

Background  Onychomatricoma was reported for the first time by Baran and Kint as a rare nail matrix tumor with specific clinical and histologic features, including a macroscopic appearance of filiform digitations originating from the nail matrix which are inserted in the nail plate. 1 The appearance of the lesion may resemble that of an “anemone.” All previous reports have been mostly from Europe, with only one case from North America. These are the first case reports from Mexico. They show rare clinical characteristics, in particular tumor involving the entire nail matrix.

HLA-DR6 association confers increased resistance to T. rubrum onychomycosis in Mexican Mestizos

Background  Onychomycosis is multifactorial in origin. Studies have suggested an autosomal dominant pattern of inheritance and human leukocyte antigen DR4 (HLA‐DR4) has been shown to protect against onychomycosis in an Ashkenazi Jewish population.

Melanonychia, melanocytic hyperplasia, and nail melanoma in a Hispanic population

OBJECTIVE Longitudinal melanonychia (LM) is a common dermatologic problem encountered in everyday practice. Its diagnostic approach is critical as it can be an early sign of nail melanoma. Racial melanonychia is the entity most frequently associated with LM. Because there are no clinical data regarding these associations in a Mexican population, we conducted a prospective study. METHODS A total of 68 consecutive patients given the clinical diagnosis of LM were included and a nail biopsy was performed to determine its cause. RESULTS Racial melanonychia was found in 48 cases (68%), 4 cases (5.7%) were associated with benign melanocytic hyperplasia, and 4 cases (5.7%) had a nail apparatus malignancy. LIMITATIONS Dermatoscopy and immunohistochemical stains were not used. Incisional transverse nail matrix biopsies were performed when melanonychia affected the middle portion of the nail plate. CONCLUSION LM is most commonly associated with racial melanonychia in the Mexican population, but in nearly 6% of cases it may be linked with nail apparatus malignancy. To our knowledge, this is the first time a study of this nature was performed in a mestizo Hispanic population.

A randomised comparative trial on the use of a hydrogel with tepescohuite extract (Mimosa tenuiflora cortex extract‐2G) in the treatment of venous leg ulcers

Tepescohuite is an extract obtained from the bark of the Mimosa tenuiflora tree and is used as an empirical treatment in wounds for its healing and antiseptic properties. Venous leg ulcers (VLUs) are a common health care problem in most countries with a high rate of morbidity. The standard of care is moist interactive healing and compression; however, the ideal topical treatment is yet to be established. This study is designed to evaluate the effectiveness and safety of M. tenuiflora cortex extract (MTC‐2G) in the treatment of VLUs in an Interdisciplinary Wound and Ostomy Care Center (IWOCC). A randomised, placebo‐controlled, double blind clinical trial was conducted to compare the use of a hydrogel containing MTC‐2G with the hydrogel alone in VLUs. The study included all patients with venous ulcers referred to the IWOCC. Laboratory tests and tissue biopsies were performed at the beginning and at the end of the study. The patients were instructed to daily cleansing followed by topical application of the hydrogel and compression. Forty‐one patients were included, 22 patients received the MTC‐2G and 19 patients received the hydrogel only. Of the 41 patients, 32 completed the study, 18 in the experimental arm and 14 in the control group, 19 were women and 13 men. The mean age of the subjects was 60 years. The mean time from presentation was 38 months. The mean surface reduction was 6·29 cm2 [confidence interval (IC) 95%: 3·28–9·29] (P = 0·0001) in the MTC‐2G group and 5·85 cm2 (95% CI: 3·58–8·12) (P = 0·001) in the hydrogel group. There was no significant difference between the groups (P = 0·815). No changes in the laboratory parameters were noted. In the histology, there were not any differences between groups either. A hydrogel containing MTC‐2G was not superior to a hydrogel alone in the treatment of VLUs.

Eumycotic mycetoma caused by Madurella mycetomatis successfully treated with antifungals, surgery, and topical negative pressure therapy

We report a 21‐year‐old farmer with a 4‐year history of a nodular plaque with fistulas and induration of adjacent skin. The lesion had been treated surgically at another hospital, but recurred 2 years later.

Fixed sporotrichosis as a cause of a chronic ulcer on the knee.

Chronic wounds are a major health care problem worldwide. Wound healing is a holistic endeavour that requires an accurate identification of the specific entities interfering with wound healing in a particular patient. We present a case of fixed sporotrichosis as the cause of a chronic ulcer in the knee. Although a culture of Sporothrix schenckii could not be obtained, a positive response to the sporotrichin skin test, a skin biopsy showed a suppurative granuloma and an adequate response to oral administration of potassium iodide confirmed the diagnosis. The identification and correction of the underlying aetiology of any chronic wound is the first and most important step to restore wound healing.

Myiasis caused by Dermatobia hominis: countries with increased risk for travelers going to neotropic areas

Here, we review the human botfly (Dermatobia hominis), which belongs to a group of Diptera generically known as “myiasis‐causing flies,” characterized by the ability of their larvae to develop in animal flesh. In addition to its medical and economic importance, there is an academic interest in this botfly because of its peculiar biology, particularly because a phoretic diptera is needed to complete the life cycle. The larvae penetrate the hosts skin, causing furuncle‐like lesions that are pruritic, painful, and resemble subcutaneous nodules, producing irreversible perforations in the skin. Although D. hominis is distributed from Mexico to Argentina, a review performed by our working group from 1999 to 2015 determined that the countries with the highest infection rates in travelers are Belize, Bolivia, and Brazil. Interestingly, infected men show a higher variation in the distribution of the lesions than in women. Many treatment schemes have been suggested, including the application of highly dense liquids to the lesion to cause anoxia in the D. hominis larvae. We showed, for the first time, a Bayesian inference between D. hominis and other myiasis‐causing flies. The flies grouped into two main clusters according to their capacity to produce facultative and obligatory myiasis, and D. hominis was phylogenetically close to Cuterebra spp.

Subungual squamous cell carcinoma of the first toe

2 Bastuji-Garin S, Rzany B, Stern RS, et al. Clinical classification of cases of toxic epidermal necrolysis, Stevens–Johnson syndrome and erythema multiforme. Arch Dermatol 1993; 129: 92–96. 3 Metry DW, Jung P, Levy ML. Use of intravenous immunoglobulin in children with Stevens–Johnson syndrome and toxic epidermal necrolysis: seven cases and review of literature. Pediatrics 2003; 112: 1430–1436. 4 Princ C, Kerdel FA, Padilla SR, et al. Treatment of toxic epidermal necrolysis with high-dose intravenous immunoglobulin. Arch Dermatol 2003; 139: 26–32.

Correlation of serum IgE levels and clinical manifestations in patients with actinic prurigo

BACKGROUND: Actinic prurigo is an idiopathic photodermatosis, the pathophysiology of which has been hypothesized to involve subtype IV type b (Th2) hypersensitive response, whereby IL4, IL5, and IL13 are secreted and mediate the production of B cells, IgE, and IgG4. OBJECTIVES: To examine the association of serum IgE levels and the clinical severity of injuries. METHODS: This case-control study comprised patients with a clinical and histopathological diagnosis of actinic prurigo, as well as clinically healthy subjects, from whom 3cc of peripheral blood was taken for immunoassay. Cases were classified by lesion severity as mild, moderate, and severe. Descriptive statistics were analyzed, and chi-square test was performed. RESULTS: We included 21 actinic prurigo patients and 21 subjects without disease; 11 patients with actinic prurigo had elevated serum IgE levels, and 10 had low serum levels. Six actinic prurigo (AP) patients with elevated serum levels of IgE had moderate injuries, 4 had severe injuries, and 1 had minor injuries. Eight out of 10 patients with normal IgE levels presented with minor injuries in the clinical evaluation. The 21 controls did not have increased serum IgE levels. CONCLUSIONS: Elevated IgE levels are associated with moderate to severe clinical lesions, suggesting that actinic prurigo entails a type IV subtype b hypersensitivity response in which Th2 cells predominate.

Necrotic ulcer caused by Trichosporon asahii in an immunocompetent adolescent

Trichosporon spp. usually cause superficial infections, although systemic disease has been reported, particularly in immunocompromised hosts where the fungus exhibits an opportunistic behaviour (Ramos JM et al., J Clin Microbiol 2004; 42: 2341–4; Kemker BJ et al., J Clin Microbiol 1991; 29: 1677–83). Previous reports have shown that any organ may be involved, including the skin. The most frequent dermatological manifestations are secondary to disseminated disease and can be seen as lichenoid or eczematous plaques, erythematous macules, splinter haemorrhages, maculopapular or cellulitis-like lesions, and Osler s or necrotic nodules. Diagnosis is usually confirmed by skin biopsy and cultures and the fungus can be identified and further analysed for subspecies (David C et al., J Am Acad Dermatol 2008; 59: s13–s15; Wolf DG et al., J Clin Microbiol 2001; 39: 4420–5; Walsh TJ et al., J Clin Microbiol 1990; 28: 1616–22).