Scabies for MBBS students

Scabies
Causative organism: Sarcoptes scabiei var. hominis (Itch mite).
Highly contagious disease
spreads in households and environments where there is intimate personal contact
Transmitted through infected clothes, linens and sexual contacts.
PATHOGENESIS
Parasite infestation occurs by close ontact or clothes or fomites of infected person------>
Mites form burrow and lays eggs------>
Sensitization occurs ------->
Clinical lesions occurs

CLASSIFICATION
Classical
Nodular scabies
Crusted (Norwegian) scabies
Bullous scabies
PREDISPOSING FACTORS
Lack of hygiene
Low socioeconomic conditions
Close physical contacts
Immunocompromisation
Vagabond
Old age
Hospital stay
Down syndrome, Organ transplant, Leukemia, AIDS patients

CLINICAL FEATURES
Pathognomonic lesion:
Burrow which is slightly elevated, greyish and tortuous lines. Vesicle or pustule containing the mite may be found found at the end of the burrow
(Definition: a linear or curvilinear papule, caused by a burrowing scabies mite)
Papules, excoriations, bulla, crust and lichenification occurs.
Pruritus is prominent symptom which is severe and usually more intense in the night.
Even after successful treatment, itch can continue and occasionally nodular lesions persist.

SITES
Finger webs
Wrists
Axilla
Nipple and Areola
Umbilicus
Lower abdomen
Genitalia
Buttock
Scrotum and penis
Face and scalp in infant
Around and underneath nails
Involvement of the genitals in males and of the nipples in females are pathognomic.
COMPLICATIONS
Local:
Secondary bacterial infections – impetigo, folliculitis, furunculosis.
Eczematization

INVESTIAGATIONS
The diagnosis is made by identifying the scabietic burrow and visualizing the mite (by extracting with a needle under microscope or using a dermatoscope).

Burrow is detected with gentian violet and then the organism is isolated with needle or scalpel and visualized under microscope.
TREATMENT
General measures
Counselling and reassurance
Maintenance of personal hygiene
Treatment of family members and close contacts at a time.
Washing of clothes and beddings.

Specific measures

Topical therapy
5% permethrin cream – 2 applications 1 week apart., Apply all over the body (except head and face in adults) and keep it for 8 to 12 hours. Then wash off .
All family members and physical contacts need to apply in the same way at same time.
25% Benzyl benzoate
Crotamiton 10% cream
10% precipitated sulphur
Malathion
Lindane
Monosulfirum

Systemic therapy
Ivermectin: single dose in case of severe infestation and in immunosuppressed patients.

1. Scabies Dr Azmiree Binte Aslam

2. Scabies Causative organism: Sarcoptes scabiei var. hominis ( Itch mite).

3. Highly contagious disease spreads in households and environments where there is intimate personal contact Transmitted through infected clothes, linens and sexual contacts.

4. PATHOGENESIS Parasite infestation occurs by close ontact or clothes or fomites of infected person Mites form burrow and lays eggs Sensitization occurs Clinical lesions occurs

5. CLASSIFICATION Classical Nodular scabies Crusted (Norwegian) scabies Bullous scabies

6. PREDISPOSING FACTORS Lack of hygiene Low socioeconomic conditions Close physical contacts Immunocompromisation Vagabond Old age Hospital stay Down syndrome, Organ transplant, Leukemia, AIDS patients

7. CLINICAL FEATURES Pathognomonic lesion: Burrow which is slightly elevated, greyish and tortuous lines. Vesicle or pustule containing the mite may be found found at the end of the burrow ( D efinition: a linear or curvilinear papule, caused by a burrowing scabies mite)

8. Papules , excoriations , bulla, crust and lichenification occurs. Pruritus is prominent symptom which is severe and usually more intense in the night. Even after successful treatment, itch can continue and occasionally nodular lesions persist.

9. Figure: scabies with secondary bacterial infection

10. SITES Finger webs Wrists Axilla Nipple and Areola Umbilicus Lower abdomen Genitalia Buttock Scrotum and penis

11. Face and scalp in infant Around and underneath nails Involvement of the genitals in males and of the nipples in females are pathognomic .

12. COMPLICATIONS Local: Secondary bacterial infections – impetigo, folliculitis, furunculosis. Eczematization

13. Systemic: Acute glomerulonephritis – when the lesions are secondarily infected by β- haemolytic streptococcal strains of 49, 55, 57, 60 and M type 2, then there is deposition of Ag-Ab in the glomerular basement membrane causing inflammation resulting in Acute glomerulonephritis.

14. INVESTIAGATIONS The diagnosis is made by identifying the scabietic burrow and visualizing the mite (by extracting with a needle under microscope or using a dermatoscope ). Burrow is detected with gentian violet and then the organism is isolated with needle or scalpel and visualized under microscope.

15. TREATMENT General measures Counselling and reassurance Maintenance of personal hygiene Treatment of family members and close contacts at a time. Washing of clothes and beddings.

16. Specific measures Topical therapy 5% permethrin cream – 2 applications 1 week apart., Apply all over the body (except head and face in adults) and keep it for 8 to 12 hours. Then wash off . All family members and physical contacts need to apply in the same way at same time.

17. 25% Benzyl benzoate Crotamiton 10% cream 10% precipitated sulphur Malathion Lindane Monosulfirum

18. Systemic therapy Ivermectin: single dose in case of severe infestation and in immunosuppressed patients.

19. 3. Symptomatic therapy Antihistamines Antibiotics if there is secondary infection: flucloxacillin For eczematization : Topical steroid

20. Thank you