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PARASITIC SKIN INFESTATIONS. Özlem Akın, M.D. Yeditepe University Hospital Department of Dermatology. LEISHMANIASIS. a protozoal disease caused by Leishmania tropica parasite, which is transmitted by the Phlebotomus sand fly.
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PARASITIC SKIN INFESTATIONS Özlem Akın, M.D. Yeditepe University Hospital Department of Dermatology
LEISHMANIASIS • a protozoal disease caused by Leishmania tropica parasite, which is transmitted by the Phlebotomus sand fly. • The reservoir hosts are the dog in the Mediterranean area, man in the Middle East and the wild rodents in Asia and Africa . • Leishmaniasis has three different morphological features ; • cutaneous leishmaniasis , • muco-cutaneous • visceral (Kala-azar ).
CUTANEOUS LEISHMANIASIS • has many local synonym such as Tropical sore, Oriental sore, Aleppo sore or Baghdad sore. • caused by Leishmania tropica protozoa, which is endemic in Asia minor, Southwest Asia, the Mediterranean and gulf regions.
CUTANEOUS LEISHMANIASIS • Modes of Infestations • The Phlebotomus sand fly is the vector, transmitting the disease from the reservoirs to human being. • Direct infection from infected sores to a traumatized skin may rarely cause the disease
CUTANEOUS LEISHMANIASIS • Children are more susceptible, where solid immunity is acquired after the first infestation. This is why some natives sometimes inoculate their children with the protozoa on the shoulder or thighs to have the disease there in order to protect the face from scarring if they are infested in the future with leishmania.
CUTANEOUS LEISHMANIASIS • Clinical Features • The disease has a very chronic course. The incubation period may take from weeks to two months from the beginning of the sand fly bite . • Leishmaniasis usually affects children more than other age groups where the face , extremities and the neck are the most common sites involved.
CUTANEOUS LEISHMANIASIS • Usually begins as a small, well-demarcated papule that may enlarge into a nodule or plaque, which may become ulcerated or verrucous. • Exposed areas are most commonly involved • Lesions are often solitary but may be multiple, with the formation of satellites or lymphatic spread • Majority of acute cutaneous infections resolve spontaneously with scarring, but some may become chronic or disseminated • Patients with disseminated form of cutaneous leishmaniasis have multiple ulcerated lesions
LEISHMANIASIS • After a variable period of time ranging from months to more than 20 years, some patients will develop mucocutaneous disease. • Mucosal lesions range from simple edema of the lips and nose, to perforation of nasal and laryngeal cartilage as well as the palate • Additional forms include leishmaniasis recidivans, a sporotrichotic pattern and ‘dry’ erythematous plaques • leishmaniasis recidivans is characterized by recurrence at the site of an original ulcer, generally within two years and often at the edge of the scar
LEISHMANIASIS • Post kala-azar dermal leishmanias syndrome is a sequel to visceral leishmaniasis that may arise several years after the successful treatment of the primary infection.
LEISHMANIASIS • Pathology: • Ulceration • Pseudoepitheliomatous hyperplasia • Mixed inflamatuar infiltrate composed of netrophils, plasma cells, lymphocytes and histiocytes • Amastigotes in dermal macrophages
LEISHMANIASIS • Diagnosis: • Skin biopsy • Montenegro skin test • uses leishmanial antigen to induce a cell mediated response • cannot distinguish between past and present infections • Can be false-negative in anergic patients with disseminated infections • Culture • Serologic and immunologic tests
LEISHMANIASIS • Differential diagnosis: • Pyoderma gangrenosum • Infectious causes of skin ulcers (streptococci, dimorphic opportunistic fungi, mixed bacterial flora) • Condiloma acuminata • Squamous cell carcinoma
Pediculosis • Lice infestation (pediculosis) is a skin infestation by tiny wingless insects. • Lice spread most frequently through person-to-person contact. • People with lice usually have severe itching. • Lice and their eggs can be found by looking through hair on the head or other parts of the body. • Treatment usually involves shampoos, creams, or lotions. • Some people require an antiparasitic drug taken by mouth.
Pediculosis • Lice are barely visible wingless insects that live by sucking blood. • They spread easily from person to person by body contact and shared clothing and other personal items. • Three species of lice inhabit different parts of the body.
Pediculosis Capitis • Head lice infest the scalp hair. • spread by personal contact and possibly by shared combs, brushes, hats, and other personal items. • a common scourge of school children of all social strata. • less common among blacks. • no association between head lice and poor hygiene or low socioeconomic status.
Pediculosis Corporis • Body lice usually infest people who have poor hygiene and those living in close quarters or crowded institutions. • They live in the seams of garments that are in contact with the skin. • Body lice are spread by sharing contaminated clothing and bedding. • Unlike head lice, body lice sometimes transmit serious diseases such as typhus, trench fever, and relapsing fever.
Pediculosis Pubis • Pubic lice (“crabs”), which primarily infest the genital area, are typically spread during sexual contact. • These lice may infest the chest hair, underarm hair, beard hair, eyebrows, and eyelashes as well.
Pediculosis • Lice infestation usually causes severe itching in the infested area. • Intense scratching often breaks the skin, which can lead to bacterial infections. • Head lice can be found by moving a fine-tooth detection comb through wet hair from the scalp outward. • Lice themselves are sometimes hard to find, but their eggs are easier to see. • Female lice lay shiny grayish white eggs (nits) that can be seen as tiny globules firmly stuck to hairs near their base.
Pediculosis • With chronic scalp infestations, the nits grow out with the hair and therefore can be found some distance from the scalp, depending on the duration of the infestation. • Nits are distinguished from other foreign material present on hair shafts by the fact that they are so strongly attached. • Adult body lice and their eggs also may be found in the seams of clothing worn close to the skin. • Public lice can be found by close inspection.
Pediculosis • Several effective prescription and nonprescription drugs are available to treat lice. • Nonprescription shampoos and creams containing pyrethrins plus piperonyl butoxide are applied for 10 minutes and are then rinsed out. • permethrin (a synthetic form of pyrethrin), applied as a liquid or as a cream, is also effective. • Lindane can be applied as a lotion or shampoo—also cures lice infestation but is not as effective as the other preparations and is not recommended for young children because of possible neurologic side effects. • malathion is highly effective at killing both adult lice and eggs, but it is not considered a first line of treatment because it is flammable, has an unpleasant odor, and must remain on the skin for 8 to 12 hours. • All louse treatments are repeated in 7 to 10 days to kill newly hatched lice. • Lice have started to become resistant to drugs and may be hard to kill. • One dose of the drug ivermectin is usually given by mouth if lice resist standard treatment.
Pediculosis • Most drug treatments also kill nits but do not remove them. • Dead nits do not have to be removed, but drugs do not always kill all nits. • Because it is not possible to distinguish between living and dead nits, doctors recommend removing them. • Nonetheless, a very small percentage of children with nits in their scalp actually have live lice. • Removal requires a fine-tooth comb and careful searching (“nit-picking”). • Because the nits are so strongly stuck to the hair, several nonprescription preparations are available to loosen them. • Nits are carried away from the scalp as the hair grows. • If there are no nits within 1/4 inch of the scalp, the person does not have any live lice.
Pediculosis • The nits of body lice are destroyed simply by throwing away infested clothing or decontaminating it by thorough laundering or dry cleaning. • For head lice, doctors do not have good evidence whether it is necessary to clean or throw away people's personal items or to exclude people from school or work.
Scabies • Scabies is caused by the itch mite Sarcoptes scabiei. • The female itch mite tunnels in the topmost layer of the skin and deposits her eggs in burrows. • Young mites (larvae) then hatch in a few days. • The infestation causes intense itching, probably from an allergic reaction to the mites. • The infestation spreads easily from person to person on physical contact, often spreading through an entire household. • In rare cases, mites may be spread on clothing, bedding, and other shared objects, but their survival is brief, and normal laundering destroys them.
Scabies • The hallmark of scabies is intense itching, which is usually worse at night. • The burrows of the mites are often visible as very thin lines up to 1/2 inch long, sometimes with a tiny bump at one end. • Sometimes, only tiny bumps are seen, many of which are scratched open because of the itching. • The burrows can be anywhere on the body except the face. • Common sites are the webs between the fingers and toes, the wrists, ankles, buttocks, nipples, and, in males, the genitals. • Over time, the burrows may become difficult to see because they are obscured by inflammation induced by scratching. • People with a weakened immune system may develop severe infestations, which produce large areas of thickened, crusted skin.
Scabies • Usually, itching and the appearance of burrows are all that are needed to make a diagnosis of scabies. • However, doctors can confirm the presence of mites, eggs, or mite feces by taking a scraping from the bumps or burrows and looking at it under a microscope.
Scabies • Treatment • can be cured by applying a cream containing 5% permethrin which is left on the skin overnight and then washed off. • For older children and adults, lindane lotion is an alternative. • With either drug, a second treatment is required a week later. • Ivermectin taken by mouth in two doses given a week apart also is effective and is especially helpful for severe infestations in people with a weakened immune system. • Even after successful treatment, itching may persist for 2 to 4 weeks because of a continued allergic reaction to the mite bodies, which remain in the skin for a while.
Scabies • The itching can be treated with mild corticosteroid cream and antihistamines taken by mouth. • Occasionally, the skin irritation and deep scratches lead to a bacterial infection, which may require antibiotics given by mouth. • Family members and people who have had close physical contact, such as sexual contact, with a person with scabies should be treated as well. • Clothing and bedding used during the preceding few days should be washed in hot water and dried in a hot dryer or dry cleaned.
