[Erythrodermic crusted scabies induced by corticosteroids treated with ivermectin. A case report]

Severe Scabies: A French Multi-centre Study Involving 95 Patients with Crusted and Profuse Disease and Review of the Literature

The aim of this multi-centre French retrospective study was to identify severe, i.e. crusted and profuse, scabies patients. Records were retrieved from 22 Dermatology or Infectious Diseases departments in the Ile-de-France from January 2009 to January 2015 to characterize epidemiology, demography, diagnosis, contributing factors, treatment features, and outcomes in severe scabies. A total of 95 inpatients (57 crusted and 38 profuse) were included. A higher number of cases was observed among elderly patients (>75 years), mostly living in institutions. Thirteen patients (13.6%) reported a history of previously treated scabies. Sixty-three patients (66.3%) had been seen by a previous practitioner for the current episode (up to 8 previous visits). Initial misdiagnosis (e.g. eczema, prurigo, drug-related eruptions, psoriasis) was documented in 41 patients (43.1%). Fifty-eight patients (61%) had already received 1 or more previous treatments for their current episode. Forty percent received corticosteroids or acitretin for an initial diagnosis of eczema or psoriasis. Median time from the onset of symptoms to the diagnosis of severe scabies was 3 months (range 0.3-22). Itch was present in all patients at diagnosis. Most patients (n=84, 88.4%) had comorbidities. Diagnostic and therapeutic approaches varied. Complications occurred in 11.5% of cases. To date, there is no consensus for diagnosis and treatment, and future standardization of is required for optimal management.

Crusted scabies in children in France: a series of 20 cases

To evaluate the risk factors for crusted scabies in children in France. The retrospective multicenter study, conducted in France, of children (aged < 18 years) with profuse and/or crusted scabies confirmed by dermoscopy and/or microscopy. Data were obtained using a standardized questionnaire. We included 20 children. The mean age was 4.5 years, and 70% of the patients were girls. Their medical history revealed a neurological pathology (agenesis of the corpus callosum; n = 1, 5.0%), prematurity (n = 1, 5.0%), Down syndrome (n = 1, 5.0%), atopic dermatitis (n = 2, 10%), and asthma (n = 2, 10.0%). Fifteen (75.0%) children were treated with steroids before being diagnosed with scabies: 12 (60.0%) with topical steroids, one (5.0%) with a systemic steroid, and two (10.0%) with inhaled steroids. One child (5.0%) lived in a precarious environment. The mean duration of pruritus was 3.4 months, and that of the skin lesions was 3.1 months. The most commonly affected areas for crusted scabies were the palms/hands (66.7%) and the armpits (33.3%). Thirteen children (65.0%) were hospitalized, 14 (70.0%) were treated with ivermectin and all received topical treatments; 85.7% were cured within an average of 38 days, but one child had a relapse 3 months later in the form of common scabies.Conclusion: The main risk factor for developing crusted scabies in France was the misdiagnosis and the use of corticosteroids, especially topical forms typically used in "healthy" children. Management of the children was effective and similar to that used in adults. What is Known: • Crusted scabies is an extremely contagious disease which is rarely reported in infancy, especially in healthy children. • The main risk factors include immunosuppression, physical debilitation, and intellectual disability. What is New: • The main risk factor of severe scabies in this study was delayed diagnosis associated with the use of topical or systemic corticosteroids. • The treatment was successful in 85.7% of cases, and 65% of children needed to be hospitalized.

[Severe crusted scabies: A "historic" case involving the death of a 52-year-old patient]

BACKGROUND

Crusted scabies, also known as Norwegian scabies, is a rare and extremely debilitating form of Sarcoptes scabiei var. hominis infestation that generally occurs in immunosuppressed patients. Herein, we report a "historic" and fatal case.

PATIENTS AND METHODS

A 52-year-old woman was admitted to the emergency department presenting crusted dermatitis together with extreme deterioration of her general condition. Her general practitioner had initiated dermo-corticosteroid therapy for suspected atopic dermatitis two months earlier, and she had been confined to bed for the previous 10 days. Her son presented pruritus that became worse at night. On examination the patient was moaning, dehydrated and confused and her entire skin was hyperkeratotic, with very thick, yellowish, cracked crusts covering 40 % of her body. Tests indicated severe water and electrolytic disorders as well as Staphylococcus aureus bacteremia. A tape test established the diagnosis of crusted scabies. The severity was grade III on the Davis clinical grading scale. The patient showed signs of multi-organ failure and was transferred to intensive care, but she died during the night.

DISCUSSION

This case is remarkable for its historic severity. In France, scabies infestation is a re-emerging disease and has been a public health priority since 2012. The rare hyperkeratotic form is not fully understood and frequently diagnosed late, in some cases with a fatal outcome.

Comparison of oral ivermectin versus crotamiton 10% cream in the treatment of scabies

OBJECTIVE

Scabies is a relatively contagious infection caused by a tiny mite (Sarcoptes scabiei). Products used to treat scabies are called scabicides because they kill scabies mites; some also kill mite eggs. The aim of this study was to compare the efficacy and safety of oral ivermectin versus crotamiton 10% cream for the treatment of scabies.

METHODS

In total, 320 patients with scabies were enrolled, and were randomized into two groups: the first group received a single dose of oral ivermectin 200 µg/kg body weight, and the second group were treated with crotamiton 10% cream and were told to apply this twice daily for five consecutive days. Treatment was evaluated at intervals of two and four weeks, and if there was treatment failure at the two-week follow-up, the treatment was repeated.

RESULTS

A single dose of ivermectin provided a cure rate of 62.5% at the two-week follow-up, which increased to 87.5% at the four-week follow-up after repeating the treatment. Treatment with crotamiton 10% cream was effective in 46.8% of patients at the two-week follow-up, which increased to 62.5% at the four-week follow-up after this treatment was repeated.

CONCLUSION

A single dose of ivermectin was as effective as one application of crotamiton 10% cream at the two-week follow-up. After repeat treatment, ivermectin was superior to crotamiton 10% cream at the four-week follow up. The delay in clinical response with ivermectin suggests that it may not be effective against all the stages in the life cycle of the parasite.