Scabies and risk of skin sores in remote Australian Aboriginal communities: A self-controlled case series study.

BACKGROUND: Skin sores caused by Group A streptococcus (GAS) infection are a major public health problem in remote Aboriginal communities. Skin sores are often associated with scabies, which is evident in scabies intervention programs where a significant reduction of skin sores is seen after focusing solely on scabies control. Our study quantifies the strength of association between skin sores and scabies among Aboriginal children from the East Arnhem region in the Northern Territory. METHODS AND RESULTS: Pre-existing datasets from three published studies, which were conducted as part of the East Arnhem Healthy Skin Project (EAHSP), were analysed. Aboriginal children were followed from birth up to 4.5 years of age. Self-controlled case series design was used to determine the risks, within individuals, of developing skin sores when infected with scabies versus when there was no scabies infection. Participants were 11.9 times more likely to develop skin sores when infected with scabies compared with times when no scabies infection was evident (Incidence Rate Ratio (IRR) 11.9; 95% CI 10.3-13.7; p<0.001), and this was similar across the five Aboriginal communities. Children had lower risk of developing skin sores at age ≤1 year compared to at age >1 year (IRR 0.8; 95% CI 0.7-0.9). CONCLUSION: The association between scabies and skin sores is highly significant and indicates a causal relationship. The public health importance of scabies in northern Australia is underappreciated and a concerted approach is required to recognise and eliminate scabies as an important precursor of skin sores.

Scabies Itch.

Itch is the cardinal symptom of scabies, present in more than 90% of the cases, generalized and intense, worsening at night, and often sparing the head. The primary complications of the itch in scabies are secondary bacterial infections and psychosocial issues leading to impairment on life quality. Currently, there are no specific data analyzing mechanisms of the itch in scabies, but the latest progress made in the understanding of host-mite interactions may help to improve understanding. Management of itch in scabies consists primarily of the treatment of the mite infestation, but sometimes the itching sensation may persist after adequate therapy.

A Case of Tinea Corporis due to Trichophyton tonsurans that Manifested as Impetigo.

A 41-year-old man visited our dermatology clinic because an eruption, which was resistant to steroid ointment treatment, had appeared on his right forearm. An oval, soybean-sized erythematous infiltrated lesion with scales and crusts was located in the central part of the extensor surface of the right forearm and showed partial erosion with attached yellow crusts. The lesion had an impetigo-like appearance. Fungal elements were confirmed from the scales by KOH examination and the fungus was identified as Trichophyton tonsurans by fungal culture and molecular method. Clinical features of T. tonsurans infection vary, wherein some patients have strong inflammatory manifestations, while others remain as asymptomatic carriers. Especially at the early stage of the infection, diagnosis is difficult because it is often misdiagnosed as eczema. We report a case of T. tonsurans infection that had impetigo-like appearance. We also studied the mechanism of the disease.

Mass Drug Administration for Scabies Control in a Population with Endemic Disease.

BACKGROUND: Scabies is an underrecognized cause of illness in many developing countries. It is associated with impetigo, which can lead to serious systemic complications. We conducted a trial of mass drug administration for scabies control in Fiji. METHODS: We randomly assigned three island communities to one of three different interventions for scabies control: standard care involving the administration of permethrin to affected persons and their contacts (standard-care group), mass administration of permethrin (permethrin group), or mass administration of ivermectin (ivermectin group). The primary outcome was the change in the prevalence of scabies and of impetigo from baseline to 12 months. RESULTS: A total of 2051 participants were enrolled; 803 were in the standard-care group, 532 in the permethrin group, and 716 in the ivermectin group. From baseline to 12 months, the prevalence of scabies declined significantly in all groups, with the greatest reduction seen in the ivermectin group. The prevalence declined from 36.6% to 18.8% in the standard-care group (relative reduction in prevalence, 49%; 95% confidence interval [CI], 37 to 60), from 41.7% to 15.8% in the permethrin group (relative reduction, 62%; 95% CI, 49 to 75), and from 32.1% to 1.9% in the ivermectin group (relative reduction, 94%; 95% CI, 83 to 100). The prevalence of impetigo also declined in all groups, with the greatest reduction seen in the ivermectin group. The prevalence declined from 21.4% to 14.6% in the standard-care group (relative reduction, 32%; 95% CI, 14 to 50), from 24.6% to 11.4% in the permethrin group (relative reduction, 54%; 95% CI, 35 to 73), and from 24.6% to 8.0% in the ivermectin group (relative reduction, 67%; 95% CI, 52 to 83). Adverse events were mild and were reported more frequently in the ivermectin group than in the permethrin group (15.6% vs. 6.8%). CONCLUSIONS: Mass drug administration, particularly the administration of ivermectin, was efficacious for the control of scabies and impetigo. (Funded by the Australian National Health and Medical Research Council; Australian New Zealand Clinical Trials Registry number, ACTRN12613000474752.).

Scabies and impetigo prevalence and risk factors in Fiji: a national survey.

BACKGROUND: Scabies is recognised as a major public health problem in many countries, and is responsible for significant morbidity due to secondary bacterial infection of the skin causing impetigo, abscesses and cellulitis, that can in turn lead to serious systemic complications such as septicaemia, kidney disease and, potentially, rheumatic heart disease. Despite the apparent burden of disease in many countries, there have been few large-scale surveys of scabies prevalence or risk factors. We undertook a population-based survey in Fiji of scabies and impetigo to evaluate the magnitude of the problem and inform public health strategies. METHODOLOGY/PRINCIPAL FINDINGS: A total of 75 communities, including villages and settlements in both urban and rural areas, were randomly selected from 305 communities across the four administrative divisions, and all residents in each location were invited to participate in skin examination by trained personnel. The study enrolled 10,887 participants. The prevalence of scabies was 23.6%, and when adjusted for age structure and geographic location based on census data, the estimated national prevalence was 18.5%. The prevalence was highest in children aged five to nine years (43.7%), followed by children aged less than five (36.5%), and there was also an indication of prevalence increasing again in older age. The prevalence of scabies was twice as high in iTaukei (indigenous) Fijians compared to Indo-Fijians. The prevalence of impetigo was 19.6%, with a peak in children aged five to nine years (34.2%). Scabies was very strongly associated with impetigo, with an estimated 93% population attributable risk. CONCLUSIONS: As far as we are aware, this is the first national survey of scabies and impetigo ever conducted. We found that scabies occurs at high levels across all age groups, ethnicities, and geographical locations. Improved strategies are urgently needed to achieve control of scabies and its complications in endemic communities.

Uncovering common bacterial skin infections.

The four most common bacterial skin infections are impetigo, erysipelas, cellulitis, and folliculitis. This article summarizes current information about the etiology, clinical presentation, diagnosis, prevention, treatment, and implications for primary care practice needed to effectively diagnose and treat common bacterial skin infections.

A 3-month-old with a blistering plaque.

Cutaneous Mastocytosis is not an uncommon condition in the pediatric setting. The eruption can have multiple clinical presentations. We present a case of a 3-month-old child with a solitary mastocytoma who was initially diagnosed with recurrent bullous impetigo. Solitary mastocytoma can present as a blister. Although bullous impetigo is a common diagnosis in children and it would be tempting to make that diagnosis in the presence of a positive skin swab culture, clinicians always have to be mindful of secondary impetiginization of another primary skin disease process.

[Cutaneous infections in bullous pemphigoid patients treated with topical corticosteroids]. / Infections cutanées chez les patients atteints de pemphigoïde bulleuse traités par dermocorticoïdes.

BACKGROUND: Potent topical corticosteroids (TCS), such as clobetasol propionate are more efficacious than systemic corticosteroids in the treatment of bullous pemphigoid (BP) and in reducing the rate of systemic infectious complications. However, TCS can have cutaneous side effects, such as atrophy and purpura. The risk of cutaneous infections due to TCS in BP is known but has never been studied, despite prolonged use of high doses. Since we noted three cases of fatal necrotizing fasciitis (NF) in patients treated with TCS for BP over a one-year period in our institution, we decided to analyse the frequency of cutaneous infections in all BP patients hospitalized in our department. PATIENTS AND METHODS: In this retrospective single-centre study, all files of patients presenting BP treated with TCS and hospitalized between April 2008 and April 2009 were reviewed. When the clinical file indicated a cutaneous infectious problem, bacteriological data were requested from the bacteriology laboratory. For each patient, clinical data, history, ongoing treatment, type of cutaneous infectious complication, general symptoms and details of outcome were collected. RESULTS: In the 30 files studied, we found ten cutaneous infections in nine patients: minor complication (three cases of impetiginisation), moderate complications (two erysipelas, one lymphangitis with sepsis, one flexor tendon phlegmon with cutaneous fistula), and severe complications with a fatal course (three NF, one of which had involved erysipelas of favourable outcome a few months earlier). These cutaneous complications occurred after various treatment times (ten days to two years) and various dosages of TCS (two-three tubes/day to two tubes every two days). Three of the nine patients with cutaneous infections had diabetes, in particular two of the three patients with FN. In contrast, four of the 21 patients without cutaneous complications had diabetes. Patients with cutaneous infections did not have more extensive BP or receive more TCS than the others. In two of three patients with NF, an immunosuppressant drug (methotrexate or mycophenolate mofetil) had been recently initiated (inferior to one month). The offending organism was Staphylococcus aureus in seven cases (methicillin-resistant in three cases) and Streptococcus A in five cases (three NF, one lymphangitis and one impetiginisation). The outcome was fatal in the three cases of NF but was favourable with local and/or systemic antibiotic therapy in the remaining cases. CONCLUSION: In this study, we noted cutaneous superinfection in nine of 30 (30%) patients receiving topical corticosteroids for bullous pemphigoid, among which were three cases of fatal NF due to streptococcus A (10%). The infectious risks associated with TCS must not be neglected, particularly since treated patients are old and fragile, and frequently have multiple well-known risk factors for NF (e.g. extensive lesions, diabetes, etc.). In the event of signs of cutaneous superinfection, especially in cases of diabetes and prolonged TCS treatment, bacteriological analysis should be conducted. Adequate treatment should be initiated without delay, especially in cases of beta-haemolytic streptococcal infection.