Evaluation of the scabicidal effect of a single dose of fluralaner in a rabbit model of crusted scabies.

Recently, scabies was included in the WHO roadmap for neglected tropical diseases 2021-2030. Till now, ivermectin is the only available oral drug that is currently approved for treating crusted scabies in humans. Concerns regarding its efficacy and safety have prompted research efforts to find new alternatives. Our study aimed to evaluate the therapeutic effect of a single dose of fluralaner in cases of crusted scabies in comparison with that of repeated weekly high doses of ivermectin. For the in vitro study, twenty adult female mites were exposed to 50 µg/ml and 100 µg/ml ivermectin and fluralaner to evaluate their effects on mites' survival. For the in vivo study, thirty-five male crossbreed rabbits were divided into 4 groups: group I (non-infected, non-treated), group II (infected, non-treated), group III (infected and treated with ivermectin in a weekly oral dose of 0.4 mg/kg body weight/rabbit for 4 weeks, starting 8 weeks post-infection), and group IV (infected and treated with fluralaner given as a single oral dose of 25 mg/kg body weight/rabbit, starting 8 weeks post-infection). Clinical, parasitological, histopathological, and biochemical assessments were done. Clinical and parasitological assays were accomplished to all infected groups starting from day 0, then on days 2, 4, 6, 8, 10, 12, 14, 21, 28, 35, 42, 49 and 56 post-treatment, while histopathological and biochemical assessments were done at the end of the 8th week post-treatment (day 56). Our results showed that fluralaner exhibited a higher acaricidal effect on adult Sarcoptes scabiei var. cuniculi when compared with ivermectin applied in the same concentration (50 µg/ml or 100 µg/ml). Concerning the in vivo study, both clinical cure and parasitological cure were noted in both treated groups, evidenced by complete absence of all clinical signs of infestation and absence of mites in all skin scrapings. However, the ivermectin-treated group showed incomplete histopathological and biochemical resolution. Interestingly, both clinical cure and negative skin scrapings were noticed earlier in the fluralaner-treated group, with no apparent side effects. Also, no significant differences were noticed in the skin sections and serum biochemical parameters when compared with those of the negative control group. We concluded that fluralaner is a promising scabicidal agent that is recommended to be studied for possible human use, especially in control programs.

Treatment of stable nonsegmental vitiligo using transdermal delivery of 5-fluorouracil by fractional CO2 laser versus intralesional injection of 5-fluorouracil, both followed by narrow-band type ultraviolet B (UVB): A comparative study.

BACKGROUND: Updates of treatment methods of stable vitiligo are needed to give better outcomes with a shorter duration of treatment. OBJECTIVE: To test the effect of transdermal 5-fluorouracil (5-FU) delivery using fractional CO2 (FrCO2 ) laser versus intralesional 5-FU injection, with narrow-band type ultraviolet B (UVB) (NB-UVB) therapy after both, in the treatment of stable vitiligo. PATIENTS AND METHODS: The present study comprised 40 patients with nearly symmetrical stable vitiligo lesions. The left side was treated with FrCO2  laser followed by topical 5-FU (FrCO2  + 5-FU), while the right side was treated with 5-FU intradermal injection. Both procedures were done at 2-week intervals for 3 sessions followed by 24 sessions of narrow-band UVB for both sides. RESULTS: Repigmentation was demonstrated on the left side of 90% of patients and the right side of 85% of patients. As much as >50% improvement was demonstrated on the left side of 50% of patients, and the right side of 55% of patients. Intralesional 5-FU showed a statistically significant difference in repigmentation compared to FrCO2  + 5-FU. CONCLUSION: Both 5-FU injection and FrCO2  + 5-FU were effective therapeutic modalities for vitiligo. Patients were more compliant with FrCO2  + 5-FU.