Scabies and systemic lupus erythematosus

Susceptibility of patients receiving chemotherapy for haematological malignancies to scabies

BACKGROUND

Scabies is a contagious dermatosis. The risk factors for its transmission remain unclear. A scabies outbreak, involving patients who were receiving chemotherapy for haematological malignancies, occurred at our hospital.

METHODS

The outbreak population was analysed to determine whether the incidence of scabies was higher among contact patients receiving chemotherapy for haematological malignancies.

RESULTS

A patient with crusted scabies was the index case, and 18 of 78 contact healthcare workers (HCWs) and 22 of 135 contact patients were diagnosed with classical scabies. Ten of 17 contact patients with haematological malignancies and 12 of 118 contact patients with other diseases were infected with scabies. The incidence rate was significantly higher among the patients with haematological malignancies (P<0.001). The patients with haematological malignancies had a significantly lower mean minimum neutrophil count than those with other diseases (1159/μL vs 3761/μL, P=0.0012). Most haematological patients did not require special nursing assistance, suggesting that the higher incidence of scabies among these patients resulted from their immunodeficiency rather than greater skin-to-skin contact with infected HCWs.

CONCLUSION

Our study suggests that patients receiving chemotherapy for haematological malignancies are more susceptible to scabies than patients with other diseases, and require stricter protection.

Crusted scabies: clinical and immunological findings in seventy-eight patients and a review of the literature

OBJECTIVES

To describe the clinical and immunological features of crusted scabies in a prospectively ascertained cohort of 78 patients.

METHODS

All patients requiring inpatient treatment for crusted scabies in the 'top end' of the northern territory of Australia over a 10 year period were prospectively identified. Demographics, risk factors, and immunological parameters were retrospectively compiled from their medical records and pathology databases.

RESULTS

More than half the patients with crusted scabies had identifiable immunosuppressive risk factors. Eosinophilia and elevated IgE levels occurred in 58% and 96% of patients, respectively, with median IgE levels 17 times the upper limit of normal. Seventeen percent had a history of leprosy but 42% had no identifiable risk factors. There was a decrease in mortality after the introduction of a treatment protocol consisting of multiple doses of ivermectin combined with topical scabicides and keratolytic therapy.

CONCLUSIONS

Crusted scabies often occurs in patients with identifiable immunosuppressive risk factors. In patients without such risk factors, it is possible that the crusted response to infection results from a tendency to preferentially mount a Th2 response. The treatment regime described was associated with a reduction in mortality. This is the largest reported case series of crusted scabies.

Pneumocystis carinii pneumonia in patients with systemic lupus erythematosus

At the University Hospital, Kuala Lumpur, Malaysia, nine patients with systemic lupus erythematosus (SLE) were treated for Pneumocystis carinii pneumonia (PCP) between January 1987 and December 1988. When they developed PCP all the patients' SLE disease course was active and eight of them were on prednisolone. Four of these eight patients were also receiving cyclophosphamide. Patients who were on more intensive immunosuppressive therapy were found to develop more severe PCP. All the patients except one were treated with high-dose cotrimoxazole. Four patients responded to antipneumocystis treatment and survived, while PCP was responsible for the death of the five non-survivors.

Scabies presenting as bullous pemphigoid-like eruption

Several diseases, at times, may be confused with scabies. We report the diagnosis and treatment of scabies in two patients. Their eruptions recurred and persisted and eventually developed blisters. The skin biopsy specimens submitted for light microscopy and immunofluorescence were considered to be consistent with bullous pemphigoid. Both patients were treated successfully with lindane and remained disease free for up to 6 months of follow-up.