Papular elastorrhexis: a distinct variant of connective tissue nevi or an incomplete form of Buschke–Ollendorff syndrome?

Papular elastorrhexis is a rare entity, possibly a form of multiple elastic tissue naevi. The cutaneous lesions in this disorder are characterized by multiple white papules usually occurring on the trunk. These tend to be nonfollicular and scattered evenly over the affected area. Histopathologically, there is a decrease of elastic fibres, that may also appear thin and fragmented. Most reported cases are sporadic but familial occurrence has been described and some authors believe that papular elastorrhexis may represent a mild form of Buschke-Ollendorff syndrome. We report an 18-year-old woman whose clinical and histopathological features were compatible with papular elastorrhexis. There was no evidence of skeletal changes or relevant family history.     

Lipomas after blunt soft tissue trauma: are they real? Analysis of 31 cases

BACKGROUND: Soft tissue trauma and lipomas are common occurrences in surgical practice. Lipomas are defined as benign tumours of adipose tissue with so far unexplained pathogenesis and aetiology. A link between preceding blunt soft tissue trauma at the site of the tumour and the formation of lipomas has been described earlier. These soft tissue tumours have been named 'post-traumatic lipomas'. OBJECTIVES: In a retrospective review, to analyse all patients with benign adipose tissue tumours treated at our institution between August 2001 and January 2007. METHODS: All cases were reviewed regarding medical history, magnetic resonance imaging findings, intraoperative findings, clinical chemistry and histology. RESULTS: In 170 patients presenting with lipomas, 34 lipomas in 31 patients were identified as post-traumatic. The mean +/- SD age of the patients with post-traumatic lipomas was 52 +/- 14.5 years. The mean time elapsed between soft tissue trauma and lipoma formation was 2.0 years (range 0.5-5). Twenty-five of the 31 patients reported an extensive and slowly resolving haematoma after blunt tissue trauma at the site of lipoma formation. The mean +/- SD body mass index was 29.0 +/- 7.6 kg m(-2). Fourteen of 31 patients presented with an elevated partial thromboplastin time. Eleven of 34 lipomas were found on the upper extremities, five on the lower extremities, 13 on the trunk, and two on the face. All tumours were located subcutaneously, superficial to the musculofascial system. Thirty-three lipomas were removed by surgical excision and one by liposuction following an incisional biopsy. Histological examination revealed capsulated and noncapsulated benign adipose tissue in all 34 tumours. CONCLUSIONS: The existence of a pathogenic link between blunt soft tissue trauma and the formation of post-traumatic lipomas is still controversial. Two potential mechanisms are discussed. Firstly, the formation of so-called post-traumatic 'pseudolipomas' may result from a prolapse of adipose tissue through fascia induced by direct impact. Alternatively, lipoma formation may be explained as a result of preadipocyte differentiation and proliferation mediated by cytokine release following soft tissue damage after blunt trauma and haematoma formation.     

999 abuse: do mothers know what they are using?

Many parents purchase topical applications without knowing what they contain, and apply them liberally to their children with dermatological disorders. In one such case, an infant developed fever, diarrhea and a small ulcer near the right labia majora which was treated with a topical cream called '999' containing dexamethasone acetate. The infant subsequently developed extensive necrotizing fasciitis. She required prolonged intravenous antibiotic use and underwent multiple surgical procedures for debridement and reconstruction. Another mother was concerned about therapeutic corticosteroids prescribed to her 11-year old daughter with eczema. She acquired the 999 cream from the Chinese mainland and applied it liberally as an emollient to her daughter's back. When assessed at the clinic, her daughter appeared cushingoid with accelerated growth velocity in BMI and weight but decelerated growth in height. Furthermore, one mother applied a large quantity of 999 on her daughter with mild eczema and another mother applied it on her son with impetigo. None of these mothers knew that they were using potent topical corticosteroids. This report serves to alert the public to avoid applying unknown topical medication on children with skin diseases. The physician caring for patients with skin disease should be aware that even steroidophobic parents might indeed be unknowingly using potent corticosteroids.     

Androgenetic alopecia and insulin resistance: are they truly associated?

Background Controversies exist regarding the association of androgenetic alopecia (AGA) with insulin resistance. Are they truly associated, or is insulin resistance just related to aging, obesity, or to the presence of metabolic syndrome? Objective To assess insulin resistance in young nonobese patients with AGA with and without metabolic syndrome. Methods The study included four equally distributed groups of age‐, sex‐, and body mass index‐matched young, nonobese subjects: 30 patients with AGA and metabolic syndrome (group 1); 30 patients with AGA and no metabolic syndrome (group 2); 30 patients with metabolic syndrome and no AGA (group 3); and 30 healthy controls (group 4). Insulin resistance based on fasting insulin levels and homeostasis model assessment of insulin resistance (HOMA‐IR) was assessed in all groups. Results Twenty‐three patients in group 1, four patients in group 2, 25 patients in group 3, and three healthy controls had insulin resistance with statistically significant differences in fasting insulin and HOMA‐IR levels between all groups, between groups 1 and 2, groups 1 and 4, groups 2 and 3, and groups 3 and 4. No significant differences existed between groups 2 and 4 or groups 1 and 3. Correlations between insulin resistance parameters, age of patients, disease duration, and stages of AGA in males and females revealed nonsignificant differences. Conclusions Patients with metabolic syndrome, with or without AGA, were significantly more insulin resistant compared with patients with AGA with no metabolic syndrome and with healthy subjects and, therefore, no true association exists between AGA and insulin resistance.     

Human nevi: no longer precursors of melanomas?

Considerable data support the idea that oncogene-induced senescence remains a barrier that needs to be overcome for malignant transformation of melanocytes. Human nevi stain positive for the senescence-associated β-galactosidase marker, suggesting that cells have lost their proliferative capacity. Most nevi harbor B-RAF or N-RAS mutations, implying that they are growth arrested via oncogene-induced senescence pathways. It remains intriguing how benign nevus cells can escape oncogene-induced senescence for malignant transformation to melanoma. The report by Tran et al. in this issue shows that current senescence markers do not distinguish nevi from melanomas, challenging the notion that nevi are growth-arrested via senescence.     

Pleomorphic fibroma and dermal atypical lipomatous tumor: are they related?

Pleomorphic fibromas represent dome‐shaped or polypoid cutaneous lesions characterized by a paucicellular and densely fibrotic background punctuated by scattered atypical to pleomorphic spindle and multinucleated giant cells. Some of these tumors will have incorporated adipose tissue, although these adipocytic areas lack distinct cytologic atypia and may represent entrapped normal periadnexal or subcutaneous adipose tissue. Nonetheless, owing to the similarity of some of the morphologic features of pleomorphic fibroma with cutaneous atypical lipomatous tumor, diagnostic confusion can ensue. The potential diagnostic challenges are further highlighted by a recent report of a lesion with histopathologic features of both. In response, we studied the presence of 12q15/ MDM2 amplification by fluorescence in situ hybridization and MDM2 expression by immunohistochemistry in a series of 15 pleomorphic fibromas to investigate whether these two entities share a common pathogenic origin. One case of cutaneous atypical lipomatous tumor was used as positive control for 12q15 amplification. All 15 cases were negative for MDM2 by immunohistochemistry with no demonstrable 12q15/MDM2 amplification by fluorescence in situ hybridization. Therefore, these two entities are best regarded as pathogenetically distinct. MDM2 immunohistochemistry or fluorescence in situ hybridization studies can be used to differentiate between the two if needed.     

Connections between nerve endings and epidermal cells: are they synapses?

Abstract: Based on electron microscopy and confocal scanning microscopy, contacts between sensory axons and the cells of the epidermis have been described: with keratinocytes, Langerhans cells, melanocytes and Merkel cells. We would like to initiate a debate on this question: “Are neuro‐epidermal connections synapses?”. Anatomically, neuro‐epidermal junctions can be considered as synapses in our opinion. If neuro‐epidermal junctions are synapses, they probably belong to the family of en passant synapses, with nerve endings passing along epidermal cells and occasionally connecting to them. In conclusion, we suggest that neuro‐epidermal junctions could be considered as true synapses, but this does not exclude non synaptic interactions.     

Acral lesions of vitiligo: why are they resistant to photochemotherapy?

Background Acral lesions of vitiligo are usually resistant to conventional lines of treatment as well as surgical interventions. Objective To clarify causes underlying resistance of acral lesions to pigmentation in vitiligo by studying some of the factors associated with mechanisms of repigmentation following photochemotherapy. Methods The study included twenty patients with active vitiligo. Skin biopsies were taken from lesional and perilesional skin of areas expected to respond (trunk and proximal limb) and skin of acral areas, before and after PUVA therapy. Sections were stained with H and E, Melan‐A, MHCII, CD1a, SCF and c‐kit protein. Results Before treatment acral areas showed significantly lower hair follicle density, melanocyte density, Langerhans cell (LC) density, epidermal MHCII expression, lesional SCF expression and perilesional c‐kit expression. Following treatment with PUVA in both non‐responsive acral and repigmenting non‐acral lesions identical immunohistochemical changes in the form of significant decrease in LC density, epidermal MHC‐II and SCF expression were observed. Conclusion The surprisingly similar histochemical changes in response to PUVA in acral and non‐acral lesions did not manifest with clinical repigmentation except in non‐acral ones. Factors such as inherent lower melanocyte density, lower melanocyte stem cell reservoirs and/or lower baseline epidermal stem cell factor may be considered as possible play makers in this respect.     

Linear atrophoderma of Moulin: a disease related to immunity or a kind of connective tissue disease?

We describe a 28‐year‐old man with linear atrophoderma of Moulin (LAM), whose serum immunological markers were abnormal (including antinuclear antibody, ribonucleoprotein, immunoglobulin M and anti‐SM antibody). In addition, however, a histological analysis identified unexpected connective tissue disease changes in this patient. We speculate that the pathogenesis of LAM is associated with immunity or that LAM itself is a kind of connective tissue disease.     

Self-tanning lotions: are they a healthy way to achieve a tan?

Self-tanning creams utilize dihydroxyacetone (DHA) as an active agent, to produce a temporary staining of the skin. DHA is a 3-carbon sugar that interacts with the protein-rich stratum corneum to produce melanoidins, which are brown chromophores. Lower concentrations of DHA produce lighter skin-staining, while higher concentrations produce darker skin-staining, resulting in the simulation of a tan for persons of all skin types. DHA is well tolerated, for both internal ingestion and topical application, with the exception of infrequent allergic reaction in some patients. However, self-tanning creams only offer a sun protection factor (SPF) of 3 to 4, with protection at the low end of the visible spectrum and limited ultraviolet A protection. In addition, this SPF is only present for several hours after application of the product, and does not last for the duration of the tan. Self-tanning creams are a method of safely simulating the appearance of a tan without photoprotection. However, other sun protection will be required.     

Animal models for atopic dermatitis: are they relevant to human disease?

Over the last decade, animal models of atopic dermatitis (AD) have received increasing attention. They include NC/Nga mice, a hapten-induced mouse model, and transgenic and knockout mouse models. Although the pathogenesis of skin inflammation elicited in these models and that in AD are not quite the same, it is pertinent to ask what these animal models really tell us about the pathogenesis and possible therapies for the disease. NC/Nga mice may yield information relevant to the dissection of the crucial components of the pathophysiology of AD rather than the assessment of potentially therapeutic agents for its treatment. A hapten-induced mouse model created by repeated application of 2,4,6-trinitrochlorobenzene (TNCB) is a simple and reproducible one. This model offers several advantages over others: by changing hapten and the mouse strain used, various types of chronic inflammation, probably reflecting heterogeneity in clinical presentation of AD, can be induced; this model is also of enormous value in its high reproducibility as well as the ease of quantitative assessment by measuring ear thickness. Among various transgenic and knockout mouse models, the IL-18-transgenic mouse is one of the closest available mouse models of human AD, although the onset of the AD-like lesions in the IL-18-transgenic mice is such a late event. Although these mice all have significant disadvantages, it is important to review the current literature on the models in the hope that one may identify useful areas for investigation.