Scabies

Pharmacotherapeutics of Scabies

1. SCABIES Dr. V. S. Swathi Assistant Professor

2. Definition Scabies is an intensified Pruritis skin problem caused by the Sarcotes scabiei hominis (Mite)

3. Epidemiology In the world, Scabies affects nearly 130 million. In India, its incidence ranges from 13-59% in rural and urban areas.

4. Typical Scabies It causes itchy rash on hands and wrists It not affects scalp/ face

5. Nodular Scabies Itchy, raised bumps/ lumps especially in the genital areas, armpits/ groin

6. Crusted Scabies/ Norwegian Scabies More severe and extremely contagious type of Scabies People develop thick crusts of skin that contain thousands of mites and eggs It develops in people with weak immune system

7. Etiology Mite called Sarcoptes scabiei hominis

8. Scabies mite life cycle

9. Pathogenesis

10. Clinical Presentation Adults Lesions at: Flexor aspects of wrists Dorsal feet Axillae Elbows Waist Buttocks Genitalia Pruritic papules, vesicles on Scrotum, Penis Infants Lesions at: Face Neck Palms Soles

11. Complications Excoriations Wide spread eczema Honey coloured crusting Post inflammatory hyperpigmentation Erythroderma Prurigo nodules Frank pyoderma Prurigo nodules

12. Diagnosis Clinical presentation Microscopic examination of skin

13. Non Pharmacological Treatment Avoid sharing of clothes and towels Use properly washed clothes Apply soothing lotion like Calamine

14. Treatment Algorithm

15. Drugs used in treatment of Scabies Drug Category Mode of action Dose Adverse affects Permethrin Topical Scabicidal Kills parasite by affecting their nerve cells 5% cream-BD for 7 days Burning Stinging Pruritis Hypersensitivity Crotamiton Topical antipruritic agent Counter irritant effect by cooling the skin 10% lotion-OD for 7 days Allergic contact dermatitis Rash Pruritis Hypersensitivity Warm sensation Sulfur Topical anti acne agent It shows keratolytic action and also have Scabicidal action 5-10% -HS-for 3 days Erythema Excessive desquamation Skin irritation Skin inflammation Hypersensitivity

16. Lindane Topical Scabicidal Kills parasite by affecting their nerve cells 1% lotion-BD Local irritation Contact dermatitis Alopecia Conjunctivitis Rash Ivermectin Anti helmenthic agent Kills parasite by affecting their nerve cells 200mcg/kg/day for 3 days like 1,2, and 8 th day-PO Asthenia Hypotension Peripheral oedema Transient tachycardia Insomnia Benzyl benzoate Topical Scabicidal Kills parasite by affecting their nerve cells 5% lotion-BD for 7 days Application site irritation Pruritis Erythema Ocular irritation Dandruff

17. Salicylic acid Topical keratolytic agent Dissolves the intracellular cement and helps in desquamation of hard skin 5% cream-BD for 7 days Stinging Peeling Scaling Dizziness Head ache Cetrizine Anti histamine Competes with histamine on effector cells and blocks histamine actions 10mg-HS -PO Somnolence Head ache Fatigue Dry mouth Malaise

18. Resources https ://www.ncbi.nlm.nih.gov/pmc/articles/PMC4614097/pdf/pch-20-395.pdf https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5165060/pdf/Dtsch_Arztebl_Int-113-757.pdf https://www.jabfm.org/content/jabfp/30/1/78.full.pdf https://bmcinfectdis.biomedcentral.com/track/pdf/10.1186/s12879-015-0983-z https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5708620/pdf/pntd.0005920.pdf