Ectoparasitic sexually transmitted diseases: scabies and pediculosis

Scabies and pediculosis are diagnosed on an almost daily basis in many dermatology offices. Whether the patient seeks medical attention because of the often unbearable itch of scabies or because of the fear of lice infestations, the physician should be on the lookout for these ectoparasitic infestations. Secondary bacterial infection, resistance to medication, and the risk of spread of the infestations to family members and other close contacts may complicate the problem. Patients frequently have to battle the myths, prejudices, and even shame that are associated with such infestations.     

Scabies and lice: review of the clinical features and management principles

Health care providers frequently encounter human infestations of scabies and lice. When a person is identified as having either of these infestations, he/she should be treated. More importantly, their close contacts should be examined and treated if needed. It is vital for dermatology nurses to understand the epidemiology, transmission, symptoms, distribution, diagnosis, complications, and treatment for scabies and lice infestations.     

Mite infestations

Mite infestations are important in dermatology because these may cause dermatologic diseases that range from papulosquamous eruptions to urticarial lesions to bullous eruptions and may spread infectious diseases. These clinical manifestations are important to recognize because mite-associated diseases may have systemic complications and may be confused with other dermatologic conditions. In treating mite infestations, oral antibiotics may be necessary. Prevention of infestation may be accomplished by pre-treating clothing with permethrin, using insect repellent N,N-Diethyl-meta-toluamide on clothing and skin, and treating animals infected with mites. This article will review etiology, clinical manifestation, and treatment of mite infestations.     

Sarcoptes scabiei infestation misdiagnosed and treated as Langerhans cell histiocytosis

The inflammatory cell infiltrate in Sarcoptes scabiei infestations often includes Langerhans cells. Scabies infestations in children may mimic Langerhans cell histiocytosis (LCH) clinically as well. We report two children with scabies who were misdiagnosed clinically and histologically as LCH and treated with systemic chemotherapy. Scabies must always be ruled out in infants and children with eczematous eruptions and inflammatory infiltrates that include histiocytes on histologic examination.     

A potpourri of parasitic infestations

Ectoparasitic infestations are common cutaneous problems. The vast majority of these are attributable to scabies and pediculosis. While these are usually readily recognizable, infestations caused by other ectoparasites, such as nonscabetic mites, may pose difficulty in diagnosis. In this article, we present a variety of ectoparasitic infestations that initially eluded diagnosis and review the gamut of ectoparasites that can cause eruptions in the skin.     

The darker side of head lice infestations

Head lice (Pediculus humanus capitis) infestations are prevalent among young children and generally not considered a health hazard. Although massive chronic head lice infestations have been documented in paleo medical literature, their association with severe iron deficiency anemia has been rarely discussed in modern medicine. A recently published case implicating a head lice infestation as the cause of death of a 12-year-old girl brings this topic to the fore. This contribution discusses the available information concerning the circumstances under which this girl died and the ongoing criminal investigation as a springboard for discussion of how head lice infestations may serve as forensic and legal evidence and as a warning sign of mental illness, abuse, neglect, and rape.     

Bed bugs,leeches and hookworm larvae in the skin

Bed bugs, leeches, and hookworm-related cutaneous larva migrans are skin infestations that are usually considered of minor importance because they produce discomfort rather than cause or transmit disease. Bed bugs have been increasing tremendously in high-income countries in recent years, causing distress to affected individuals and economic loss. Infestation by land leeches causes mainly unpleasant skin reactions, whereas infestation by aquatic leeches may be more dangerous, leading to anemia and in severe cases, to death. Cutaneous larva migrans produces an intense pruritus that can be exasperating for the patient and cause sleep disturbance. An overview is given of these three infestations with a discussion of the causative agents, transmission, clinical manifestations, diagnosis, and treatment.     

Life-threatening stings, bites, infestations, and parasitic diseases

Bites, stings and infestations can be fatal. Anaphylaxis to vespids and bees can be prevented with immunotherapy. Patients should be referred to an allergist. The acute care and prevention of arthropod injury is discussed below.     

Vulvar infections: beyond sexually transmitted infections

The vulva is an under‐studied area of the female genitourinary tract which is prone to maceration, overgrowth of organisms, and atypical presentations of common dermatologic conditions. In current practice, dermatologists must recognize and manage vulvar infections and infestations beyond the more commonly recognized sexually transmitted infections. Herein, this article reviews the literature on a selection of under‐recognized viral, bacterial, fungal, and parasitic vulvar infections and infestations.     

DEMOGRAPHIC STUDY OF HEAD LICE INFESTATIONS IN SACRAMENTO COUNTY SCHOOL CHILDREN

Head lice infestations have become a problem in school children in Sacramento County. An open study was conducted to determine how widespread head lice infestations were among preschool and elementary school children in Sacramento County and to see how effective a newly marked ever-the-counter pediculicide containing 0.3% pyrethrins synergized by 3.0% piperonyl butoxide was. The public health nurse for this study visited the homes of all reported patients infested with head lice. She verified and provided the pyrethrins-based treatment for 248 children, aged 6 months to 12 years. The children were Caucasian, Mexican-American, black and other ethnic backgrounds and from low, middle and upper income levels. All the patients were successfully treated, and the school children were able to return to their classs in a short time.     

Clinical studies evaluating abametapir lotion, 0.74%, for the treatment of head louse infestation

Background

There is a need for better control of head louse infestations. Abametapir is an inhibitor of metalloproteinases critical for louse survival and egg development. The efficacy of abametapir lotion, 0.74%, was assessed for its ability to clear head louse infestations after a single application.

Methods

Two randomized, double‐blind, multicenter, vehicle‐controlled studies were conducted in subjects aged 6 months and older to compare the effectiveness of abametapir lotion versus vehicle control for eliminating head louse infestations without nit combing. Abametapir lotion was applied to dry hair for 10 minutes on day 0 and then rinsed with water. The primary endpoint was the proportion of index subjects (youngest household member with ≥ 3 live lice at screening) in the intent‐to‐treat population who were louse free at all follow‐up visits through day 14. Older household members with one or more live lice at screening were designated as nonindex subjects and treated as per the index subject within their household.

Results

In the intent‐to‐treat population (index subjects, N = 216), 81.5% of subjects treated with abametapir lotion were louse free through day 14 after a single treatment, versus 49.1% with vehicle (P < 0.001). For the combined index and nonindex population (N = 704), 85.9% were louse free through day 14 in the abametapir group, versus 61.3% in the vehicle group (P < 0.001). The most frequently reported adverse events were erythema (4.0%), rash (3.2%), and skin burning sensation (2.6%).

Conclusion

Abametapir lotion, 0.74%, was effective at clearing active head louse infestations through day 14 in subjects aged 6 months and older. All adverse events (including one serious but unrelated to study drug) resolved uneventfully.     

Bedbugs: an update on recognition and management

The common bedbug (Cimex lectularius) is increasingly prevalent and a source of concern and questions for patients. In addition to a range of cutaneous presentations and potential for serious sequelae, bedbug bites cause significant psychological distress and create an economic burden associated with infestation control. Recognition of characteristic entomology, clinical presentation, diagnostic features and differential diagnosis can support expedient identification of patients exposed to infestations and support their appropriate management.     

Recent immunologic considerations regarding the itch and treatment of scabies

Scabies continues to be a major public health problem. Recent findings reveal that these mites produce substances that modulate the host's immune response resulting in the latency period prior to symptoms. In terms of treatment, two cases of ivermectin resistance have come to fore in Australia in patients treated over fifty times with the agent. Additionally, work in the development of vaccination of hosts with antigenic midgut proteins of mites to control ectoparasitic infestations continues.     

Bedbugs

Cimex lectularius (the "bedbug") is an insect that feeds nocturnally, taking a requisite blood meal from a sleeping human or other parasitized host. Immunological reactions to bedbug saliva vary, but typically, bites yield erythematous and pruritic papules. The face and distal extremities, areas uncovered by sleeping clothes or blankets, are preferentially involved. Until the late 1990s, bedbug infestations in the United States were declining. Resurgence is attributed to increased travel and resistance to insecticides. Although hepatitis or human immunodeficiency virus is not effectively transmitted by the bedbug, pruritus and the fear and perceived violation of an infestation can be debilitating. Bedbugs are small but robust, and their ability to remain ensconced in crevices within the bedroom makes eradication difficult. As more patients present with bedbug bites, physicians must possess the knowledge to diagnose, treat, and educate with regard to bedbug bites and bedbug infestations.     

Book Review

Book reviewed in this article
Cutaneous infestations and insect bites , eds.: Milton Orkin & Howard I. Maibach     

New and emerging therapies in pediatric dermatology

Many of the dermatologic conditions for which children seek medical attention are caused by infectious organisms. Several medications have recently become available or are on the horizon for the treatment of pediatric skin infections and infestations. Treatment of tinea capitis with fluconazole, itraconazole, and terbinafine, antibiotic therapy for staphylococcal skin infections, cidofovir for the treatment of verrucae vulgaris and molluscum contagiosum and ivermectin for scabies and head lice are discussed.     

睡眠不足在慢性瘙痒性皮肤病中的表现及处理

慢性瘙痒性皮肤病与睡眠不足有一定的联系。已有文献报导睡眠不足对患者的行为、生理及心理健康有不良的影响,降低了患者的生活质量。该文论述了慢性瘙痒性皮肤病引起睡眠不足的病因,对睡眠不足的常规治疗方案进行了概括,对如何治疗受睡眠不足困扰的皮肤病患者给予建议。正确的治疗不仅能改善皮肤病症状且能提高患者的整体生活质量。     

Arthropod Bites, Stings, and Infestations: Their Prevention and Treatment

Readily available information as to the management of arthropod bites, stings, and infestations is important to have but often difficult to find. This article brings such information together in one reference for use by the practicing pediatrician, dermatologist, and family practitioner. Preventive measures are stressed and therapy is outlined for each entity; the rationale for many of the interventions is discussed. It is not the intent of this paper to cover each subject comprehensively.     

Dermoscopy and entomology (entomodermoscopy)

Although dermoscopy has been primarily designed for aiding the in vivo diagnosis of skin tumors, recent advances indicate it is also useful in the diagnosis of common skin infections and infestations. As such, dermoscopy connects the research fields of dermatology and entomology into one field of “entomodermoscopy”. In this article we give an overview on the current applications of entomodermoscopy.     

Ektoparasitosen

Ectoparasites or epidermal parasites include a very heterogenous group of infections of the outer layers of the skin. Worldwide the most common are scabies, lice, tungiasis, and hookworm-induced cutaneous larva migrans. In recent years, bed bug infestations in hotels or vacation homes seem to have become more frequent. Demodex folliculorum and Demodex brevis are found in the facial and scalp hair follicles in 95% of individuals. Classic Demodex folliculitis is often overlooked in differential diagnostic considerations. This inflammatory sebaceous gland disease as well as Demodex blepharitis both provide a diagnostic and therapeutic challenge. Permethrin can be used topically against demodicosis. Vacationers who go barefoot on beaches in tropical Africa, South America and subtropical Asia risk infestations from female sand fleas. The lesions can be curetted or removed with a punch biopsy, then treated with antiseptics or even systemic antibiotics if a secondary infection develops. Cutaneous larva migrans is one of the most common imported ectoparasite infections from the tropics. Topical treatment measures include thiabendazole or cryotherapy. If the infestation is severe, systemic antihelminthics or ivermectin can be employed.