Microbiology - Scabies and Pediculosis

Scabies and pediculosisScabies and pediculosis

Ziad Elnasser, MD, Ph.DZiad Elnasser, MD, Ph.D

ScabiesScabiesSarcoptes scabiei or the itch mite.Sarcoptes scabiei or the itch mite.

Burrows resides in human skin.Burrows resides in human skin.

Eggs, Larvae, adult (Incomplete Eggs, Larvae, adult (Incomplete metamorphoses)metamorphoses)

Arachnid, 4 pairs of legs, 0.35mm.Arachnid, 4 pairs of legs, 0.35mm.

EpidemiologyEpidemiology

Worldwide, Sexual promiscuity, Worldwide, Sexual promiscuity, poverty, poor hygiene overcrowding, poverty, poor hygiene overcrowding, and malnutrition.and malnutrition.

Intimate personal contact, casual Intimate personal contact, casual contact or dust samples.contact or dust samples.

Extent of clinical manifestation is Extent of clinical manifestation is related to level of cleanliness. related to level of cleanliness.

Clinical manifestationsClinical manifestations

Intense itching especially at night.Intense itching especially at night.Erythematous papules, excoriations Erythematous papules, excoriations

and occasionally vesicles.and occasionally vesicles. Interdigital web spaces, wrists, Interdigital web spaces, wrists,

axillary folds, periumbilical skin, axillary folds, periumbilical skin, pelvic girdle, penis and ankles.pelvic girdle, penis and ankles.

Classic linear burrowsClassic linear burrows..

DiagnosisDiagnosis

Clinical presentation.Clinical presentation.

Skin scraping and demonstration of Skin scraping and demonstration of the the

mite microscopically.mite microscopically.

ComplicationsComplications

Secondary impetiginization.Secondary impetiginization.

Eczematous eruption.Eczematous eruption.

Scabies incognito if corticosteroids Scabies incognito if corticosteroids are used.are used.

Delayed hypersensitivity reactionDelayed hypersensitivity reaction..

Norwegian scabiesNorwegian scabies

Severe variant.Severe variant.

Institutionalized persons, down Institutionalized persons, down syndrome, and AIDS patients.syndrome, and AIDS patients.

Hyperkeratotic crusted nodules.Hyperkeratotic crusted nodules.

Secondary bacterial infections, Secondary bacterial infections, septicemia and death.septicemia and death.

TreatmentTreatment

1% solution of Lindane not for infants, 1% solution of Lindane not for infants, pregnant women or after a bath.pregnant women or after a bath.

5 % cream Permethrin safer.5 % cream Permethrin safer. 6% – 10% precipitated sulfur in petrolium 6% – 10% precipitated sulfur in petrolium

daily for 3 days.daily for 3 days. Antipruritic drugs.Antipruritic drugs. Treat secondary infections.Treat secondary infections. Ivermectin in severe cases.Ivermectin in severe cases. Treat all contacts and linenTreat all contacts and linen..

preventionpreventionGloves.Gloves.

Prophylactic treatment for close Prophylactic treatment for close contacts.contacts.

Isolation and the use of disposable Isolation and the use of disposable itemsitems..

Pthirus pubisPthirus pubis

Crab louse.Crab louse. Could be found other than genital region.Could be found other than genital region. 2mm in length, powerful legs, hair 2mm in length, powerful legs, hair

attachment, moves slowly.attachment, moves slowly. Incomplete metamorphosis, eggs, nymph Incomplete metamorphosis, eggs, nymph

and adult.and adult. Eggs operculated, shiny, stick to hair (nitsEggs operculated, shiny, stick to hair (nits))

Clinical manifestationsClinical manifestationsPruritis.Pruritis.Maculopapular rash.Maculopapular rash.Excoriation.Excoriation.Eye lashes scaling.Eye lashes scaling.Skin thickening, macular swellings, Skin thickening, macular swellings,

hyperpigmentations, Subcutaneous hyperpigmentations, Subcutaneous hemorrages (Vagabond’s disease).hemorrages (Vagabond’s disease).

DiagnosisDiagnosis

Clinical manifestation.Clinical manifestation.

Nits, nymphs or adult louse.Nits, nymphs or adult louse.

TreatmentTreatment

Lindane.Lindane.

Permethrin.Permethrin.

Antipruritic drugs.Antipruritic drugs.

Gardnerella vaginalisGardnerella vaginalis

Hemophilus vaginalis, Hemophilus vaginalis, Corynebacterium vaginalisCorynebacterium vaginalis..

Gram variable, although amino acids and Gram variable, although amino acids and fatty acids analysis shows gram positive, fatty acids analysis shows gram positive, oxidase and catalase negativeoxidase and catalase negative

Enriched media, beta hemolytic colonies Enriched media, beta hemolytic colonies on human blood.on human blood.

Endotoxin but no lipid A.Endotoxin but no lipid A.

EpidemiologyEpidemiology

69% presence in the vagina.69% presence in the vagina.

No signs or symptoms.No signs or symptoms.

100% Bacterial vaginosis, male 100% Bacterial vaginosis, male urethra.urethra.

PathogenesisPathogenesis

Pili and adherence to McCoy cells.Pili and adherence to McCoy cells.Hemolysin (Cytolytic toxin).Hemolysin (Cytolytic toxin).Normal flora with phospholipase Normal flora with phospholipase

activity.activity.Associated with premature rupture of Associated with premature rupture of

the membranes.the membranes.Serum resistant.Serum resistant.

Clinical manifestationsClinical manifestations

Bacterial vaginosis:Bacterial vaginosis: Present with mixed anaerobic flora.Present with mixed anaerobic flora. Predispose to bacterial vaginitis.Predispose to bacterial vaginitis. Fishy odor discharge.Fishy odor discharge. Vulvar burning or pruritis.Vulvar burning or pruritis. Gram stain of vaginal fluid rather than by culture.Gram stain of vaginal fluid rather than by culture.

Urinary tract infection: Infrequent, difficult to Urinary tract infection: Infrequent, difficult to diagnose.diagnose.

Bacteremia: obstetrics events.Bacteremia: obstetrics events. Neonatal infection.Neonatal infection.

DiagnosisDiagnosis

Small pinpoint colonies.Small pinpoint colonies.

Beta hemolysis on human blood.Beta hemolysis on human blood.

Blood culture in SPS free bottles.Blood culture in SPS free bottles.

Catalase and oxidase neg, Na Catalase and oxidase neg, Na hippurate positive.hippurate positive.

TreatmentTreatment

Penicillin.Penicillin.AmpicillinAmpicillinGentamycin.Gentamycin.Metronidazole.Metronidazole.Clindamycin.Clindamycin.