SCABIES is a skin condition which is very common in dermatology. Its a concise review for beginners.

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