Crusted Scabies as a Suitable Disease for Teledermatology: A Study of 2 Cases

Background Teledermatology has been available for several years now, but the COVID-19 pandemic has highlighted its importance, especially in remote communities. Crusted scabies (CS) presents a unique clinical picture that favors telediagnosis. Patients with neurological diseases, as well as homeless, HIV-infected patients and people with impaired immunological function, are at risk. Clusters of CS have been reported in French Guyana, and these were associated with human T-lymphotropic virus infections. CS has also been reported in Aboriginal Australian communities. Objective Teledermatology is especially useful in cases of CS, as it is a disease that affects areas that are in need of medical services. At the same time, CS presents a unique clinical picture. The objective of this presentation is to fuel the clinical suspicion and detection of patients with this debilitating condition. Methods Relatives of patient 1 contacted our clinic for teledermatology appointments. General practitioners from health services sent images of the second patient. Results Case 1 involved an older woman living in a nursing home with Alzheimer disease, which was severe enough to constrain her to bed. We recommended that her relatives (who had sent images) collect skin scrapings in a container. These scrapings were sent to a clinical analysis laboratory where microscopic potassium hydroxide preparation revealed the presence of Sarcoptes mites. Treatment with oral ivermectin and topical permethrin resulted in the complete resolution of the lesions. Case 2 involved a homeless, HIV-positive, 42-year-old male. The images were sent by clinicians from local health services. This patient was also treated with oral ivermectin and permethrin lotion. We recognize that this case would need further diagnostic workup, but it is highly indicative of CS. Conclusions CS is one of the most suited diseases for the practice of teledermatology for widespread, large, hyperkeratotic fissured plaques covered with abundant, silvery scales for which the expression “once seen, never forgotten” is highly applicable. These cases are gratifyingly simple to treat, and patients benefit from rapid clinical improvement. Prompt diagnoses prevent outbreaks of scabies for relatives and medical personnel, since these skin crusts contain large numbers of scabies mites. CS has been increasingly reported but poorly recognized, and it has often been misdiagnosed as psoriasis. Images, such as those shown in this presentation, are unique and are enough to raise strong clinical suspicion. Conflicts of Interest None declared.

Crusted Scabies as a Suitable Disease for Teledermatology: A Study of 2 Cases (Preprint)

BACKGROUND Teledermatology has been available for several years now, but the COVID-19 pandemic has highlighted its importance, especially in remote communities. Crusted scabies (CS) presents a unique clinical picture that favors telediagnosis. Patients with neurological diseases, as well as homeless, HIV-infected patients and people with impaired immunological function, are at risk. Clusters of CS have been reported in French Guyana, and these were associated with human T-lymphotropic virus infections. CS has also been reported in Aboriginal Australian communities. OBJECTIVE Teledermatology is especially useful in cases of CS, as it is a disease that affects areas that are in need of medical services. At the same time, CS presents a unique clinical picture. The objective of this presentation is to fuel the clinical suspicion and detection of patients with this debilitating condition. METHODS Relatives of patient 1 contacted our clinic for teledermatology appointments. General practitioners from health services sent images of the second patient. RESULTS Case 1 involved an older woman living in a nursing home with Alzheimer disease, which was severe enough to constrain her to bed. We recommended that her relatives (who had sent images) collect skin scrapings in a container. These scrapings were sent to a clinical analysis laboratory where microscopic potassium hydroxide preparation revealed the presence of <i>Sarcoptes</i> mites. Treatment with oral ivermectin and topical permethrin resulted in the complete resolution of the lesions. Case 2 involved a homeless, HIV-positive, 42-year-old male. The images were sent by clinicians from local health services. This patient was also treated with oral ivermectin and permethrin lotion. We recognize that this case would need further diagnostic workup, but it is highly indicative of CS. CONCLUSIONS CS is one of the most suited diseases for the practice of teledermatology for widespread, large, hyperkeratotic fissured plaques covered with abundant, silvery scales for which the expression “once seen, never forgotten” is highly applicable. These cases are gratifyingly simple to treat, and patients benefit from rapid clinical improvement. Prompt diagnoses prevent outbreaks of scabies for relatives and medical personnel, since these skin crusts contain large numbers of scabies mites. CS has been increasingly reported but poorly recognized, and it has often been misdiagnosed as psoriasis. Images, such as those shown in this presentation, are unique and are enough to raise strong clinical suspicion.

Active case detection methods for crusted scabies and leprosy: A systematic review

Background Crusted scabies is endemic in some remote Aboriginal communities in the Northern Territory (NT) of Australia and carries a high mortality risk. Improvement in active case detection (ACD) for crusted scabies is hampered by a lack of evidence about best practice. We therefore conducted a systematic review of ACD methods for leprosy, a condition with similar ACD requirements, to consider how findings could be informative to crusted scabies detection. Methods and principle findings We conducted systematic searches in MEDLINE, CINAHL, Scopus and the Cochrane Database for Systematic Reviews for studies published since 1999 that reported at least one comparison rate (detection or prevalence rate) against which the yield of the ACD method could be assessed. The search yielded 15 eligible studies from 511. Study heterogeneity precluded meta-analysis. Contact tracing and community screening of marginalised ethnic groups yielded the highest new case detection rates. Rapid community screening campaigns, and those using less experienced screening personnel, were associated with lower suspect confirmation rates. There is insufficient data to assess whether ACD campaigns improve treatment outcomes or disease control. Conclusion This review demonstrates the importance of ACD campaigns in communities facing the highest barriers to healthcare access and within neighbourhoods of index cases. The potential benefit of ACD for crusted scabies is not quantified, however, lessons from leprosy suggest value in follow-up with previously identified cases and their close contacts to support for scabies control and to reduce the likelihood of reinfection in the crusted scabies case. Skilled screening personnel and appropriate community engagement strategies are needed to maximise screening uptake. More research is needed to assess ACD cost effectiveness, impact on disease control, and to explore ACD methods capable of capturing the homeless and highly mobile who may be missed in household centric models.