Scabies is a skin infection caused by the Sarcoptes scabiei mite. It causes an itchy rash and affects nearly 130 million people worldwide, with prevalence rates in India ranging from 13-59% in rural and urban areas respectively. Scabies presents as itchy papules and vesicles located typically on hands, wrists, feet, and genitalia. It can develop into more severe forms like nodular or crusted scabies in immunocompromised individuals. Treatment involves topical scabicides like permethrin or oral ivermectin. Proper hygiene and avoiding shared items can help prevent transmission.

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