scabies and pediculosis

1. Scabies
DR SUBODH KUMAR SHAH

2. Etiology
 caused by Sarcoptes scabiei.
Transmission:
 Intimate prolonged contact, e.g., as within the household.
 Fomite transmission (clothing and bedding).
Epidemiology:
 Age: occur at any age, a disease of children.
 Sex: No gender predilection.
Predisposing factors:
 Lower socioeconomic status, crowding, and poor hygiene.

3. Clinical Features
Symptoms:
 Asymptomatic for the first 4 weeks.
 Severe itching, “worse at night”. Similar symptoms may be present in several
family members/close contacts.

4. Morphology
 Primary lesions:
 Burrows: Is the pathognomonic lesion of scabies.
 Appears as a serpentine, thread-like, grayish or darker line, varying in
length from a few mm to a cm.

5. Secondary lesions:
 Pustules: due to secondary infection,
 Eczematized lesions: In infants and children,the lesions are eczematized and
crusted
 Nodular lesions: Persistent nodular lesions are seen on the scrotal and penile
skin, anterior axillary folds, and in groins

6. Scabies in infant: multiple
papulovesicular
lesions on palms. Many lesions
eczematous.
nodular lesions of genitalia

7. Sites of predilection

8. Treatment:
General principles:
 depends on correct application of medication. Scabicides should be applied
effectively to the whole body (below the jaw line in adults)including genitals,
soles of feet and skin under the free edge of the nails.
 Treat all members of the family simultaneously, even if asymptomatic.
 Ordinary laundering is adequate for bed linen.
 All clothing need not be treated because the mites anyway die in unworn
clothes in about 7 days.
 Itching may last for several days and does not require retreatment with
scabicides.
 Symptomatic treatment with antihistamines is usually adequate.

9. Specific treatment

10.  Complications
 Secondary infection with S. aureus and Strep. pyogenes is frequent.
 Eczematization is a frequent in infants

11. Pediculosis (Louse Infestation)
Etiology: Two species:
 Pediculus humanus capitis (causing scalp infestation),
 Pediculus humanus corporis (causing body and clothing infestation),
 Phthirus pubis (causing infestation of pubic area, axillae, and eyelashes).

12. Epidemiology
 Prevalence: Very common.
 Age: Affects children more than adults.
 Transmission: Spreads by: Head-to-head contact and fomites (shared
combs).

13. Clinical features
Symptoms:
 Severe itching, initially around the sides and
back and then all over the scalp.
Signs:
 Nits are easily seen, especially in the occipital
area.

15. Treatment:
 Permethrin 1% is the treatment of choice.
 Others include gamma benzene hexachloride
1%.