Scabies is caused by the human itch mite Sarcoptes scabiei, which burrows under the skin and lays eggs. It is highly contagious through direct skin-to-skin contact or contact with infested clothing or bedding. Symptoms include intense itching that is usually worst at night. Diagnosis is made by identifying the mites, eggs, or burrows under microscopic examination of skin scrapings. Treatment involves topical scabicides like permethrin or oral medication like ivermectin. Complications can include secondary skin infections if scratching occurs.

2. SCABIES
BY DR. ABDULLAH SHAH

3. WHAT IS SCABIES?
 SCABIES IS A SKIN CONDITION CAUSED BY INFESTATION OF HUMAN ITCH MITE
KNOWN AS SARCOPTES SCABIEI
 THIS MITE IS USUALLY PASSED FROM SKIN TO SKIN. IT CAN ALSO BE TRANSMITTED
THROUGH INFESTED CLOTHING OR BEDDING(SHORT PERIOD)
 SCABIES IS A CONDITION THAT AFFECTS PEOPLE WORLDWIDE, IRRESPECTIVE OF
RACE OR SOCIAL STANDING.
 A PERSON WITH A SCABIES INFESTATION USUALLY WILL HAVE BETWEEN 10 AND
15 MITES.
 SCABIES IS EASILY SPREAD. IT JUST REQUIRES DIRECT, EXTENDED SKIN-TO-SKIN
CONTACT WITH SOMEONE WHO IS INFECTED.
 THE WORLD HEALTH ORGANIZATION ESTIMATES THAT THERE ARE MORE THAN
300 MILLION CASES OF SCABIES WORLDWIDE EACH YEAR (WHO).

4. STRUCTURE:
 SARCOPTES SCABIEI VAR HOMINIS I.E AN OVOID
BODY
 FEMALE MITE IS 0.4MM LONG AND 0.3MM BROAD
WHILE MALE MITE IS 0.2MM LONG AND 0.15MM
BROAD
 BODY IS CREAMY WHITE HAS 4 PAIRS OF SHORT
LEGS, HAS ANTERIOR TWO PAIRS ENDS IN
PEDUNCLES TIPPED WITH SMALL SUCKERS
 IN FEMALE, REAR TWO PAIRS OF LEGS ENDS IN LONG
BRISTLES WHEREAS IN MALE, BRISTLES ON 3RD AND
PEDUNCLE WITH SUCKER ON 4TH PAIR OF LEGS.

5. LIFE CYCLE:
 ADULT FEMALE BURROW AND DEPOSIT EGGS
 EGGS HATCH AND RELEASE LARVAE
 LARVAE MOULT INTO NYMPHS
 BOTH LARVAE AND NYMPHS ARE FOUND IN SHORT BURROWS
CALLED MOULTING POUCHES
 COPULATION OCCUR AFTER THE MALE PENETRATES THE MOULTING
POUCHES OF FEMALE ADULT
 IMPREGNATED FEMALE LEAVES THEIR POUCHES AND EXCAVATE A
PERMANENT BURROW IN WHICH THEY LAY EGGS.
 APPROXIMATELY 40-50 EGGS LAID

6. LIFE CYCLE OF MITE:

7. CONTINUE…

8. SYMPTOMS:
PATIENTS WILL C/O : ITCHING/PRURITIS:
 IT IS USUALLY THE MOST OBVIOUS MANIFESTATION OF SCABIES.
 IT IS GENERALLY WORST AT NIGHT AND WHEN THE PATIENT IS
WARM.
 THE ONSET OCCURS 3–4 WEEKS AFTER THE INFECTION IS
ACQUIRED, AND COINCIDES WITH A WIDESPREAD ERUPTION OF
INFLAMMATORY PAPULES.

9. PRESENTATION IN BABIES:
IN BABIES AND YOUNG TODDLERS
THE COMMONLY INFECTED SITES ARE:
 HEAD
 FACE
 NECK
 PALMS
 SOLES

10. PRESENTATION IN ELDERS:
COMMON SITES FOR THE RASH IN OLDER CHILDREN AND ADULTS INCLUDE:
 WRIST
 ELBOW
 ARMPIT
 BETWEEN FINGERS
 NIPPLE
 PENIS
 WAIST
 BELTLINE
 BUTTOCKS

11. NORWEGIAN (CRUSTED) SCABIES:
 NORWEGIAN SCABIES IS HIGHLY
CONTAGIOUS DUE TO THE
LARGE NUMBER OF PARASITES
LIVING ON THE HOST, POSSIBLY
CLOSE TO 1 MILLION MITES.
 THIS VARIETY IS DIFFERENTIATED
BY VESICLES AND THE
FORMATION OF THICK CRUSTS
OVER THE SKIN.
 ALTHOUGH THERE ARE
EXPONENTIALLY MORE MITES
PRESENT THAN IN CLASSIC
SCABIES, NORWEGIAN SCABIES
ITCHES MUCH LESS AND OFTEN
NOT AT ALL.
Norwegian Scabies:

12. TRANSMISSION:
THERE ARE A NUMBER OF WAYS THAT SCABIES CAN BE SPREAD.
FOR EXAMPLE:
 PROLONGED SKIN-TO-SKIN CONTACT, SUCH AS HOLDING HANDS
 SKIN-TO-SKIN CONTACT, SUCH AS WHILE HAVING INTERCOURSE
 SHARING CLOTHING, BEDDING, OR TOWELS THAT HAVE BEEN USED
BY SOMEONE WITH A SCABIES INFECTION

13. APPROACH TO DIAGNOSES:
 THE RASH AND BURROWS ARE THE MAIN SIGNS THAT ARE USED TO
DETERMINE IF A PATIENT HAVE A SCABIES INFESTATION.
 TO CONFIRM A VISUAL DIAGNOSIS BY REMOVING A MITE FROM A
BURROW WITH A NEEDLE OR SKIN SCRAPING.
 THE SAMPLE IS EXAMINED UNDER A MICROSCOPE TO CONFIRM THE
PRESENCE OF MITES OR EGGS.

14. TREATMENT:
ACCORDING TO THE AMERICAN ACADEMY OF DERMOTOLOGISTS
(AAD), SOME COMMON TOPICAL MEDICINES USED TO TREAT SCABIES
INCLUDE:
 5% PERMETHRIN CREAM
 MALATHION 0.5%
 25% BENZYL BENZOATE LOTION
 10% SULFUR OINTMENT
 10% CROTAMITON CREAM
 1% LINDANE LOTION(GAMA BENZENE HEXACHLORIDE)

15. TREATMENT CONTINUES…
 OTHER MEDICATIONS INCLUDES:
 ANTIHISTAMINES FOR ANNOYING SYMPTOMS
 ORAL SCABICIDE i.e. IVERMECTIN
 STEROIDS (FOR PERSISTANT ITCHY NODULES)

16. COMPLICATIONS:
 ECZEMATOUS CHANGES.
 ‘SCABIES INCOGNITO’
 FOLLICULITIS OR IMPETIGO
 GLOMERULONEPHRITIS