Audrey W. Tan

Sweet's syndrome: a spectrum of unusual clinical presentations and associations.

Background  Sweets syndrome (SS) is the prototypic neutrophilic dermatosis. First described in 1964, the characterization of new clinical associations, unique histopathological findings and clinical variants have stimulated much interest and discussion recently. However, the prevalence of these unusual variants and clinical associations within a single cohort of patients, has not been described.

High-dose intravenous immunoglobulins in the treatment of toxic epidermal necrolysis: an Asian series.

Toxic epidermal necrolysis (TEN) is a severe, immune‐mediated, mucocutaneous reaction resulting in extensive keratinocyte apoptosis. High‐dose human intravenous immunoglobulins (IVIG) have been proposed as an effective treatment for TEN. Retrospective data from 8 patients with TEN and 4 patients with Stevens‐Johnson syndrome‐toxic epidermal necrolysis (SJS‐TEN) overlap treated with high‐dose IVIG were analysed. The total dose of IVIG administered was 2 g/kg body weight, with the exception of 2 patients who received a total dose of 1.5 g/kg body weight. Their mean age was 49.9 ± 18.8 years (range, 19 to 70 years). The mean time from the first sign of skin lesion or mucosal or epidermal detachment to commencement of IVIG was 8.7 ± 5.5 days (range, 3 to 22 days). Of the 11 patients who survived, the mean time to objective response was 3.6 ± 1.9 days (range, 2 to 8 days). The length of stay (LOS) in hospital was 20.4 ± 8.0 days (range, 10 to 37 days). The survival rate was 91.6%. One patient developed permanent mucocutaneous sequelae following TEN. There were no adverse reactions to IVIG. We conclude that high‐dose IVIG may be a safe and effective therapy for Asian patients with TEN.

Acne vulgaris: a review of antibiotic therapy

Antibiotic therapy has been integral to the management of inflammatory acne vulgaris for many years. Systemic antibiotics work via antibacterial, anti-inflammatory and immunomodulatory modes of action, and have been found to be useful in managing moderate-to-severe acne. Commonly prescribed antibiotics include tetracyclines, erythromycin and trimethoprim, with or without sulfamethoxazole. In selecting the appropriate antibiotic for patients needing to receive topical or systemic antibiotic therapy, the clinician should take into account the severity of the acne, cost-effectiveness, the safety profile of the drug and the potential for development of resistance. The widespread and long-term use of antibiotics over the years has unfortunately led to the emergence of resistant bacteria. The global increase in the antibiotic resistance of Propionibacterium acnes may be a significant contributing factor in treatment failures. It is therefore essential that clinicians prescribing antibiotics for the treatment of acne adopt strategies to minimise further development of bacterial resistance. This includes addressing compliance issues, using combination therapies, avoiding prolonged antibiotic treatment, and avoiding concomitant topical and oral antibiotics with che-mically dissimilar antibiotics.

Treatment of toxic epidermal necrolysis in AIDS with intravenous immunoglobulins

Summary Individuals with AIDS are at higher risk of developing severe cutaneous adverse drug reactions. We report two AIDS patients with drug‐induced toxic epidermal necrolysis (TEN). The suspected drugs were discontinued. Both patients were treated with intravenous human immunoglobulins at a dose of 1 g/kg body weight per day for two consecutive days and both experienced a good outcome. Intravenous immunoglobulin potentially lowers the morbidity and mortality of TEN and shortens the duration of the patients hospitalization.

Melanization in basal cell carcinomas: Microscopic characterization of clinically pigmented and non‐pigmented tumours

Clinical and microscopic pigmentation may affect the treatment outcomes in basal cell carcinoma. However, there have not been any in‐depth histopathological comparisons between clinically pigmented and non‐pigmented basal cell carcinomas with regards to microscopic melanization. The aims of our study were to determine the proportion of pigmented basal cell carcinomas presenting to the National Skin Centre in Singapore, to characterize the histological pattern of melanization and to perform a semi‐quantitative analysis of the degree of microscopic melanization of the tumours. Patients with clinical features and histologically confirmed basal cell carcinomas were recruited. Demographic data and clinical characteristics were recorded and basal cell carcinoma sections were examined for histological subtype and pattern of melanization. Twenty‐five Chinese patients with 30 basal cell carcinomas were recruited. Three of the five clinically non‐pigmented and all of the clinically pigmented basal cell carcinomas had microscopic evidence of melanization. Microscopic melanization in clinically non‐pigmented basal cell carcinomas was present only focally or in the centre of the tumour mass. Both groups of basal cell carcinomas may be colonized by melanocytes. Two morphological types of melanocytes, a dendritic and round cell type, were identified. Future research is required to evaluate if the degree of microscopic melanization influences the treatment outcome of basal cell carcinomas.

Characterization of the inflammatory cell infiltrate in herald patches and fully developed eruptions of pityriasis rosea.

Background.  Pityriasis rosea (PR) is a common cutaneous papulosquamous disorder affecting young adults. Previous studies have suggested possibilities of a viral aetiology and the involvement of cell‐mediated immunity, but these remain unproven to date.

A comparative study of clinical characteristics, work-up, treatment, and association to malignancy in dermatomyositis between two tertiary skin centers in the USA and Singapore

Background  To date, no study has compared the clinical characteristics, malignancy associations, and treatment of dermatomyositis in predominantly Caucasian vs. Asian populations.

Drug interactions in dermatological practice

Systemic drugs are increasingly used in the treatment of dermatological diseases. Due to the high prevalence of polypharmacy, dermatologists are increasingly faced with the complex problem of drug interaction. Unlike adverse drug reactions, which are often unpredictable, drug interactions can be avoided. This article presents the significant drug interactions that are encountered in clinical practice, with the interactions categorized into those involving antimicrobials, immunosuppressants, antimalarials and colchicine, retinoids and psychiatric medications. There are few commonly used drugs that often cause drug interactions. These include ciclosporin, azole antifungal drugs, erythromycin, sulfonamides and rifampicin, and dermatologists should be alert whenever encountering them. A section on interactions of drugs with health supplements, herbs and food is also included, in view of the increasing use of alternative and complementary therapies in many parts of the world.

Dermatofibrosarcoma protuberans: A clinicopathological analysis of 10 cases in Asians

Dermatofibrosarcoma protuberans (DFSP) is a locally aggressive cutaneous neoplasm that exhibits a marked tendency for recurrence after local excision. This case series aims to study the clinical, histological and immunohistochemical features of DFSP in Asians. Ten patients with DFSP diagnosed between 1992 and 2001 were reviewed. There were more women than men in a ratio of 4:1. There were six Chinese, two Malays, one Indian and one Eurasian. The mean age was 38 years. The duration of each lesion before excision varied from 6 months to 27 years. Fifty per cent of tumours occurred on the trunk. On histology, all the lesions were dermal‐centred spindle cell tumours, extending to the subcutis, and exhibited the characteristic storiform pattern. One tumour also demonstrated fibrosarcomatous changes. Two tumours were of the rare pigmented variant (Bednar tumour). Immunohistochemistry with CD34 was positive in all cases, except the fibrosarcomatous area of one tumour, which was negative for CD34. For comparison, six cases of deep‐penetrating dermatofibroma were stained for CD34 and all showed an absence of CD34 expression. Wide excision of the tumour was performed in all cases of DFSP. There was no recurrence after mean follow up of 6 years (range 2.25–9.5 years).

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.