Reactive Epidermal Hyperplasia and Angiogenesis of the Rear (REAR): A Proposed Unifying Name for Senile Gluteal Dermatosis and Prurigiform Angiomatosis.

Senile gluteal dermatosis (SGD) is a common but seldom recognized condition. It is characterized clinically by unilateral or bilateral hyperkeratotic, lichenified plaques on the gluteal area, being attributed to prolonged sitting, particularly in the elderly. SGD also encompasses the recently proposed entity of prurigiform angiomatosis. Histologically, there are features of lichenification, such as epidermal hyperplasia and a preserved granular layer, with prominent dermal angioproliferation. We report 4 cases of this condition as well as novel findings of variably increased mast cells and superficial lymphatic vessels in addition to the proliferation of dermal blood vessels. We propose a unifying name for Reactive Epidermal hyperplasia and Angiogenesis of the Rear (REAR) to encapsulate the characteristic clinical and histological features of this distinct entity.

Changes in connexin 43 in inflammatory skin disorders: Eczema, psoriasis, and Steven-Johnson syndrome/toxic epidermal necrolysis.

BACKGROUND: Connexin 43 (Cx43) plays a central role in the inflammatory response and wound healing. Targeting Cx43 expression reduces inflammation in a variety of injuries. The expression pattern of Cx43 has not been described for many inflammatory skin diseases. OBJECTIVES: To describe the expression patterns of Cx43 in eczema, psoriasis, Steven-Johnson syndrome/toxic epidermal necrolysis. METHODS: Archival skin biopsies from patients with eczema, psoriasis, and Steven-Johnson syndrome/toxic epidermal necrosis were identified and examined, with sister sections stained for Cx43 and imaged by confocal microscopy. All samples were compared to age and site-matched normal skin controls. RESULTS: Epidermal Cx43 is reduced in acute eczema, absent in regions of spongiosis, and is highly elevated in subacute and chronic eczema. In plaque psoriasis, Cx43 is overexpressed in areas with psoriasiform hyperplasia with a fish-scale-like appearance but is lost in regions surrounding neutrophil microabscesses. Cx43 staining is strong in the neutrophils within these microabscesses. In SJS/TEN, Cx43 expression is elevated in areas bordering normal tissue but is rapidly lost in areas of keratinocyte necrosis. CONCLUSIONS: Dynamic changes in Cx43 levels are seen in inflammatory skin diseases and may represent future potential therapeutic targets.

Retiform Purpura as a Complication of Microsphere Emboli Following Transarterial Chemoembolization for Primary Hepatocellular Carcinoma: A Case Report and Literature Review.

We report an elderly man with hepatocellular carcinoma who developed a rash after undergoing transarterial chemoembolization (TACE). On examination, there was a reticulated macular pigmentation over the chest and upper abdomen. Skin biopsy revealed foreign material that occluded the small dermal cutaneous vessels. These structures were perfectly spherical, homogeneously eosinophilic, and were also nonrefractile. They had a maximum diameter of 40 µm, consistent with the size of the microspheres used in TACE. TACE is a palliative measure used to treat hepatocellular carcinoma in patients who are not surgical candidates. Vaso-occlusive manifestations of the skin are rare occurrences, with only 8 reported cases. Seven cases attributed this to nontarget embolization of the hepatic falciform artery and 1 case postulated that collateral supply of the targeted area allowed for hematogenous migration of the occluding beads via the microcirculation. Pertaining to treatment, all patients were treated with oral nonsteroidal anti-inflammatory agents to good effect, with 1 patient receiving additional laser treatment and another having local steroid injections. Prognosis is excellent, because the skin lesions tend to resolve within a year. Several methods have been suggested to prevent these vaso-occlusive skin complications, including prophylactic application of ice or placing the tip of the microcatheter distal to the origin of the hepatic falciform artery and falciform artery.

Indeterminate cell histiocytosis in a Chinese patient with progressive and extensive nodular lesions and mixed indeterminate cell and macrophage-monocyte lineage.

Indeterminate cell histiocytosis (ICH) is an extremely rare cutaneous neoplastic disorder. It has the immunophenotypic features of both Langerhans and non-Langerhans cell histiocytosis. We report here a case of a healthy young Chinese woman who presented with disfiguring, thick, infiltrated cutaneous nodules on the face, trunk and extremities which appeared progressively over a period of 4 years. No systemic involvement has been detected so far. Results of a skin biopsy showed diffuse dermal infiltration of histiocytoid cells with indented nuclei and positive staining for S100 and CD1a and negativity for CD207 (langerin). Admixed within were some CD68-positive foamy histiocytes and multinucleated giant cells with focal expression of CD163. Although the clinical presentation is more typical of progressive nodular histiocytosis, the histology and immunoprofile is consistent with ICH. Our report adds to the limited case reports in the current literature of ICH in the Chinese population.

Atopic dirty neck or acquired atopic hyperpigmentation? An epidemiological and clinical study from the National Skin Centre in Singapore.

BACKGROUND: 'Atopic dirty neck' is a poorly understood acquired hyperpigmentation in patients with atopic dermatitis (AD). OBJECTIVE: To report a single-centre experience with synthesis of this entity's features. METHODS: All patients with AD with dirty neck seen over a 5-month period at the National Skin Centre were invited to participate. RESULTS: Out of 544 AD patients examined, 78 (14.3%) had acquired pigmentation of the neck. The majority had moderate-to-severe underlying eczema. Histopathology showed increased epidermal melanin and dermal melanophages, a thickened basement membrane and a dense superficial perivascular infiltrate. CONCLUSION: Acquired atopic hyperpigmentation has a high prevalence, particularly in adolescent Asian males. Clinico-pathological correlation suggests it results from both frictional melanosis and post-inflammatory hyperpigmentation. The rippled appearance and the onset in adolescence are probably due to accentuation of the juxta-clavicular beaded lines. Optimal control of eczema may improve and potentially prevent the development, which is of importance considering the psychosocial impact of the condition.

Fas-ligand staining in non-drug- and drug-induced maculopapular rashes.

BACKGROUND: Morphologically and histopathologically, drug- and non-drug-induced maculopapular rashes can be almost indistinguishable. It has been postulated that Fas-ligand (Fas-L) is involved in the pathogenesis of drug rashes but not in the genesis of rashes, such as viral exanthems, that are not induced by medications. AIM: This study sought to determine if epidermal Fas-L is a distinguishing feature in the pathology of drug and non-drug maculopapular rashes. METHODS: Archived skin biopsies of patients with a confirmed diagnosis of drug or non-drug maculopapular rashes (n = 10 each) and positive and negative controls were retrieved for immunohistochemical staining for Fas-L. The proportion of Fas-L-positive skin biopsies were compared. The presence of tissue eosinophilia was also evaluated. RESULTS: Ten percent of non-drug-induced rashes were Fas-L positive compared to 50% of drug rashes (p = 0.05). Twenty percent of non-drug exanthems had moderate tissue eosinophilia, while 60% from drug rashes had moderate to dense tissue eosinophilia (p = 0.17). CONCLUSION: There is a trend toward Fas-L being more prevalent in the epidermis of drug maculopapular rashes, although this did not reach statistical significance. This is possibly because of the small sample size.

Progressive trichodysplasia spinulosa in a patient with chronic lymphocytic leukaemia in remission.

A 70-year old Caucasian man with chronic lymphocytic leukaemia developed trichodysplasia spinulosa 2 months after ceasing chemotherapy. Histological features characteristic to this condition include dilated and enlarged hair follicles, hyperplastic hair bulbs, hyperplasia of inner root sheath cells with numerous large, eosinophilic, trichohyaline granules, and hypercornification. Although he was in remission for chronic lymphocytic leukaemia, lesions were slowly progressive 15 months after cessation of chemotherapy. We also describe a painless pull-test where spicules can be easily plucked and assessed microscopically for inner root sheath keratinization, or observed with surface microscopy in a clinic setting.

Squamous cell carcinoma and Bowen's disease of the skin in Singapore.

INTRODUCTION: Non-melanoma skin cancer is one of the commonest cancers in Singapore and worldwide. The aim of our study was to evaluate the demographic and clinicopathological patterns of squamous cell carcinoma (SCC) and Bowen's disease (BD) of the skin, in order to better understand the characteristics of these tumours in our population. MATERIALS AND METHODS: Histologically proven cases of SCC and BD seen at our centre between 2002 and 2003 were retrospectively analysed according to age, sex, race, predisposing factors such as immunosuppression and ultraviolet therapy, site and size of tumour, histological differentiation and subtype, and treatment method. RESULTS: A total of 161 patients were studied--81 with SCC, 68 with BD, and 12 with both tumours. There were 199 tumours in total--105 SCC and 94 BD. For both SCC and BD, males outnumbered females (ratio of 2.4:1 and 1.5:1 respectively); patient age averaged 72.9 years and 66.8 years respectively; and Chinese were the majority race. The mean duration to presentation was 21.2 months for SCC compared with 39.9 months for BD, and common symptoms were itch, pain and bleeding for both. The mean tumour size was 19.0 mm and 18.5 mm, and the commonest site was the head and neck for both. CONCLUSIONS: SCC and BD show rather similar patient characteristics, with a predominance among males, having a predilection for the head and neck region, and with a tendency towards slow growth. As incidences increase worldwide, it is important for healthcare providers to be adept at recognising and managing nonmelanoma skin cancers.