Updated evidence-based clinical practice guidelines for the diagnosis and management of melanoma: definitive excision margins for primary cutaneous melanoma.

INTRODUCTION: Definitive management of primary cutaneous melanoma consists of surgical excision of the melanoma with the aim of curing the patient. The melanoma is widely excised together with a safety margin of surrounding skin and subcutaneous tissue, after the diagnosis and Breslow thickness have been established by histological assessment of the initial excision biopsy specimen. Sentinel lymph node biopsy should be discussed for melanomas ≥ 1 mm thickness (≥ 0.8 mm if other high risk features) in which case lymphoscintigraphy must be performed before wider excision of the primary melanoma site. The 2008 evidence-based clinical practice guidelines for the management of melanoma (http://www.cancer.org.au/content/pdf/HealthProfessionals/ClinicalGuidelines/ClinicalPracticeGuidelines-ManagementofMelanoma.pdf) are currently being revised and updated in a staged process by a multidisciplinary working party established by Cancer Council Australia. The guidelines for definitive excision margins for primary melanomas have been revised as part of this process. Main recommendations: The recommendations for definitive wide local excision of primary cutaneous melanoma are: melanoma in situ: 5-10 mm margins invasive melanoma (pT1) ≤ 1.0 mm thick: 1 cm margins invasive melanoma (pT2) 1.01-2.00 mm thick: 1-2 cm margins invasive melanoma (pT3) 2.01-4.00 mm thick: 1-2 cm margins invasive melanoma (pT4) > 4.0 mm thick: 2 cm margins Changes in management as a result of the guideline: Based on currently available evidence, excision margins for invasive melanoma have been left unchanged compared with the 2008 guidelines. However, melanoma in situ should be excised with 5-10 mm margins, with the aim of achieving complete histological clearance. Minimum clearances from all margins should be assessed and stated. Consideration should be given to further excision if necessary; positive or close histological margins are unacceptable.

Ulcerative necrobiosis lipoidica responsive to colchicine.

Necrobiosis lipoidica is an uncommon granulomatous disease of unknown aetiology. Few treatments have emerged with consistent efficacy and the ulcerated form of necrobiosis lipoidica can be particularly difficult to treat. A 56-year-old non-diabetic woman with chronic ulcerative necrobiosis lipoidica unresponsive to other therapies was commenced on colchicine treatment. Complete resolution of the ulcers was observed after 2 months' therapy with colchicine 500 µg twice daily.

Recognition and management of common ectoparasitic diseases in travelers.

This review article summarizes the ectoparasitic diseases likely to be seen by a Western dermatologist. The article aims to cover both endemic diseases and those likely to present in the returning traveler. Tungiasis is due to the gravid sand flea (Tunga penetrans) embedding into the stratum corneum of a human host. As the flea is a ground dweller, lesions are usually present on the feet and are classically periungual. The sand flea is eventually shed spontaneously but to reduce the infection risk, early surgical removal is recommended. Infestation by the Diptera species of fly causes myiasis, which may be primary, secondary, or accidental. The botfly (Dermatobia hominis) is one of the causes of primary myiasis covered in this article. Traditionally, botfly larvae are forced to partially emerge by occluding the breathing apparatus, following which manual extraction can occur. Alternatively, the larvae can be surgically removed. The common bed bug (Cimex lectularius) has experienced a resurgence over the past 10 years. Bites are typically arranged in clusters or a linear fashion and vary from urticated wheals to hemorrhagic blisters. Treatment is symptomatic with antihistamines and topical corticosteroids. In addition, bed bugs need to be eradicated from furniture and soft furnishings. Ticks are part of the Arachnid class of joint-legged animals and can transmit a variety of infections. This article briefly discusses Mediterranean spotted fever, Rocky Mountain spotted fever, and Lyme disease as well as describing tick avoidance measures. Scabies (Sarcoptes scabiei var hominis) is highly contagious and widely distributed around the world. It is common in the returning traveler and can require a high index of suspicion to diagnose. The treatment of choice in the US, UK, and Australia is permethrin 5% dermal cream, applied on two occasions, 1 week apart.

Surgical excision margins for primary cutaneous melanoma.

BACKGROUND: Cutaneous melanoma accounts for 75% of skin cancer deaths. Standard treatment is surgical excision with a safety margin some distance from the borders of the primary tumour. The purpose of the safety margin is to remove both the complete primary tumour and any melanoma cells that might have spread into the surrounding skin.Excision margins are important because there could be trade-off between a better cosmetic result but poorer long-term survival if margins become too narrow. The optimal width of excision margins remains unclear. This uncertainty warrants systematic review. OBJECTIVES: To assess the effects of different excision margins for primary cutaneous melanoma. SEARCH STRATEGY: In August 2009 we searched for relevant randomised trials in the Cochrane Skin Group Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (Issue 3, 2009), MEDLINE, EMBASE, LILACS, and other databases including Ongoing Trials Registers. SELECTION CRITERIA: We considered all randomised controlled trials (RCTs) of surgical excision of melanoma comparing different width excision margins. DATA COLLECTION AND ANALYSIS: We assessed trial quality, and extracted and analysed data on survival and recurrence. We collected adverse effects information from included trials. MAIN RESULTS: We identified five trials. There were 1633 participants in the narrow excision margin group and 1664 in the wide excision margin group. Narrow margin definition ranged from 1 to 2 cm; wide margins ranged from 3 to 5 cm. Median follow-up ranged from 5 to 16 years. AUTHORS' CONCLUSIONS: This systematic review summarises the evidence regarding width of excision margins for primary cutaneous melanoma. None of the five published trials, nor our meta-analysis, showed a statistically significant difference in overall survival between narrow or wide excision.The summary estimate for overall survival favoured wide excision by a small degree [Hazard Ratio 1.04; 95% confidence interval 0.95 to 1.15; P = 0.40], but the result was not significantly different. This result is compatible with both a 5% relative reduction in overall mortality favouring narrower excision and a 15% relative reduction in overall mortality favouring wider excision. Therefore, a small (but potentially important) difference in overall survival between wide and narrow excision margins cannot be confidently ruled out.The summary estimate for recurrence free survival favoured wide excision [Hazard Ratio 1.13; P = 0.06; 95% confidence interval 0.99 to 1.28] but again the result did not reach statistical significance (P < 0.05 level).Current randomised trial evidence is insufficient to address optimal excision margins for primary cutaneous melanoma.

Fatal adverse drug reaction to trimethoprim.

BACKGROUND: Trimethoprim is the antibiotic of choice for treating uncomplicated community acquired urinary tract infections. However, before prescribing any drug it is vital to obtain a detailed drug history to exclude possible drug allergy. OBJECTIVE: We present the case of a fatal adverse drug reaction due to trimethoprim. We discuss some of the problems that led to the patient's death, and consider how to prevent similar events. DISCUSSION: Re-exposing a patient to a drug suspected of causing an adverse reaction is associated with considerable risk of morbidity and mortality. A detailed history is vital to correctly diagnose drug allergies but, even so, it is not always possible to identify the causative agent. Following an adverse drug reaction, health professionals must take appropriate steps to avoid inadvertently re-prescribing the culprit drug. This is essential to avoid the tragic outcome highlighted in this case.

Childhood sarcoidosis presenting with extensive cutaneous lesions, bilateral hilar lymphadenopathy and severe hypercalcaemia.

A 9-year-old boy with a history of atopic dermatitis presented with a 4-month history of an asymptomatic papular eruption. This was predominantly perioral in distribution with lesser involvement of the neck, arms and trunk. Investigations revealed severe hypercalcaemia of 3.77 mmol/L (normal range 2.10-2.60) and bilateral hilar lymphadenopathy. The diagnosis of sarcoidosis was supported by granulomata in skin and lymph node biopsies on histopathological examination. Prednisolone (2 mg/kg/day) rapidly normalized serum calcium.

Current options for the treatment of impetigo in children.

Impetigo contagiosa is a common, superficial, bacterial infection of the skin characterised by an inflamed and infected epidermis caused by Staphylococcus aureus, Streptococcus pyogenes or both. The less common bullous impetigo is characterised by fragile fluid-filled vesicles and flaccid blisters, and is invariably caused by pathogenic strains of S. aureus. In bullous impetigo, exfoliative toxins are produced, although these are restricted to the area of infection and bacteria can be cultured from the blister contents. In the rare variant, staphylococcal scalded skin syndrome, the exfoliative toxins are spread haematogenously from a localised source causing widespread epidermal damage at distant sites.