Infections And Infestations Flashcards
What features do head lice have ? (3 points)
- claw on each of the 6 legs to cling firmly onto host skin and hair
- can survive without a host up to 3 days (55 hours)
- can survive underwater
What is the life cycle of head lice?
2-3 weeks
What are the limitations of head lice? (2 points)
- do not survive on household pets
- do not jump or fly from host to host
- prefer clean hair
What are nits? (3 points)
- Greyish white oval Lice eggs.
- These are laid by the adult female
- hatch around 7-10 days
Where are the nits attached? (2 points)
- on the hair shaft Around 0.5cm from the scalp
- cementing substance not easily dislodged keeps the nit in place
What do nits >1cm from the scalp indicate?
Nits have most likely hatched
What are the symptoms of head lice? (5 points)
Intense itchiness on the scalp and hair shaft
- behind the ears
- on the crown
- at the nape of neck
- facial hair elf, eyebrows, eyelashes
- scratching may lead to secondary bacterial infection
How are headline detected? (2 points)
- lower the head over pale surface and comb the hair from root to tip. Conditioner may help
- life portions of hair around ears, crown or nape of neck to check for nits
What are the differential diagnoses of head lice? (2 points)
- dandruff (white spears easily dislodged)
- dermatitis (itchy, but no nits present
What are the general rules for head lice treatment? (7 points)
- use pediculicide to treat actual infestations (not for prophylaxis)
- check all family members
- follow directions carefully. Do not shorten the waiting time
- do not share articles that have come into contact with infected persons head, neck or shoulders
- wash brushes and combs in some pediculicide or very hot water.
- brush hair nightly (breaks female louses legs and prevents egg laying)
- wash clothes on hot wash
What can be done with clothing or linen that cannot be washed? (In the treatment of head lice)
-dry clean, hot iron, or bag in plastic for a few days
What are the different pediculicide treatments? (5 points)
- paraplus aerosol
- full marks mousse
- a lices shampoo
- parasidose lice repellant spray
- lice blaster
What is paraplus aerosol? (3 points)
- 0.25% malathion, 0.5% permethrin, 2% piperonyl butoxide
- not heat resistant (do not blow dry), but chlorine resistant
- spray in short bursts over DRY hair until fully covered and leave for 10mins
What is full marks mousse? (4 points)
- 0.5% phenothrin
- spray foam on hair and spread from root to tip. Dry. Leave for 30 min. Wash off with regular shampoo
- repeat in 7 days. Up to 3 applications
- not for children under 6 months
What is A lices shampoo? (4 points)
- 1% malathion shampoo
- lather into wet hair and leave for at least 10 min
- repeat in 1 week
- also used to treat pubic lice
What is parasidose lice repellant spray? (2 points)
- essential oils of eucalyptus, clove, palmarosa, lavender, mint, rose, citronella, ylangylang, geranium, pettigrain
- prevents lice infestation but based on weak evidence
What is lice blaster? (4 points)
- contains herbs and essential oils
- natural preparation but weak evidence
- apply to dry hair and leave on for 20min. Rinse off with warm water
- repeat in 1 week
What are the general advice for head lice shampoos? (6 points)
- avoid mucous membranes and eyes
- use at least 20ml depending on hair length
- shampoo into dry or damp scalp (only use a little water)
- Leave on for 10min and rinse off
- use fine toothed nit comb to remove nits
- soaking in 50/50 water/vinegar mix may help loosen glue holding the nits onto hair shaft
When should head lice be referred?
-when Secondary infection is present (weeping, swollen glands)
What are head lice?
Small wingless insects that feed on human blood
Ectoparasites
What is threadworms also known as? (2 points)
- pin worm
- enterobios vernicularis
What is the prevalence of threadworms in NZ?
-accounts for 95% of human worm infestations
What is a threadworm?
-intestinal parasite passed on to humans when eggs are swallowed unknowingly
What is the life cycle of a threadworm? (5 points)
- egg hatches out of duodenum
- larvae pass into large intestine and grow into threadworms
- adult female moves down the gut to anus to lay eggs
- the glue sticking the eggs to the anus irritates the host causing scratching
- eggs will stick onto fingernails and be transferred to mouth, other people, food, furniture, etc.
What are the signs and symptoms of threadworms? (4 points)
- sometimes asymptomatic
- usually itching around anus at night
- white cotton pieces (5-10mm) wriggling around anus or outside of bowel motion
- restless sleep, irritability, bedwetting, loss of appetite
What information must be gathered from the patient regarding threadworm treatment? (6 points)
- confirmation of threadworm
- treatments tried and efficacy
- number in family
- age and weight
- other diseases (esp. Liver problems)
- pregnancy/breastfeeding
How are threadworms treated? (7 points)
- medicines and hygiene measures to prevent re-infection
- treat whole family, tell child’s school teacher
- thorough washing of hands and fingernails with soap and water esp. Before eating and after the toilet
- children to wear close fitting underpants at night to stop scratching
- shower before bed and again in morning to remove eggs laid at night
- wash bed linen, bed clothes, underwear in hot water, vacuum bedroom and toilet floor to get rid of dry eggs
- disinfect toilet seat, bath and shower
What are the anthelmintic agents to treat threadworm? (2 points)
- Pyrantel ebonate
- Mebendazole
What is pyrantel ebonate? (6 points)
- combantrin chocolate squares
- paralyses worms which are then excreted
- dosed by body weight (10mg/kg)
- treats threadworm, roundworm and hookworm
- okay for children from 1 year old
- avoid in acute liver disease
What is mebendazole? (7 points)
- deworm, Vermont, combantrin-1.
- interferes with worm glucose absorption causing starvation
- one dose for all treatment (100mg)
- treats threadworm, roundworm, hookworm, whipworm and tapeworm
- avoid in pregnancy, acute liver disease, children
What is scabies? (2 points)
- Parasitic infestation of skin
- caused by 8 legged itch mite sarcoptes scabei var. hominins
What is the nature of the scabies parasite? (2 points)
- female burrows into skin to lay her eggs
- scabies is highly contagious but only transmitted by direct skin contact
What are the signs and symptoms of scabies treatment? (6 points)
- intense itching, especially at night 1-8 weeks after contact
- mites or eggs present at end of red threadlike burrows (wrists me between fingers and toes
- linear ink stains remaining under skin - burrows made by scabies
- secondary bilateral itchy rash due to sensitisation of mite exudate and coat (wrists my hands, axillae, nipples, genitals, head and neck in infants
- secondary bacterial infection
- close personal or family contacts may be asymptomatic
How long can the scabies sensitisation rash last for?
2-4 weeks after treatment,
This does not indicate treatment failure.
What are the general treatment principles for scabies? (10 points)
- treat individual and any close personal or family contacts (if they are asymptomatic they may reinfect the person as well as themselves)
- do not over treat, 1-2 treatments is adequate, otherwise refer
- wait until after initial scabei ice treatment to use topical CS
- soap and water alone will not work. Need a scabicide
- can be spread by sharing clothes or bedding
- scabies do not live in furniture or carpets
- follow directions for applying scabicide a exactly
- clothes worn against the skin in the last week must be washed, not laundered or dry cleaned. Wash sheets but not blanket/duvet
- children
What are the different scabicides used? (4 points)
- gamma benzene hexachloride 1%
- malathion 0.5%
- permethrin 5%
- crotamiton
What is gamma benzene hexachloride 1%? (6 points)
- lindane, benhex cream
- warm-cool bath first, dry thoroughly, cool down
- massage into body neck down (infants include face, neck, ears and scalp)
- Leave for 8-12 hours, then wash off
- usually once application sufficient
- avoid in pregnancy and young children
What is malathion 0.5%? (6 points)
- A lices, malathion lotion
- warm cool bath first, dry thoroughly then cool down
- massage from the neck down, ensure coverage under fingernails
- leave for 24 hours then wash off
- reapply 7-10 days later
- caution in children
What is permethrin 0.5%? (8 points)
- lyderm cream, A-scabies lotion
- warm cool bath, dry thoroughly, cool down
- massage a thin layer onto whole body from neck down
- leave for 8-14 hours (but best left until 24 hours)
- usually one application is enough
- do not use more than 2 tubes
- transient stinging burning sensation but non staining and odourless
- caution in children 70 years, and people sensitive to permethrin, pregnancy and breastfeeding
What is crotamiton? (5 points)
- eurax, itch-soothe
- good antipruritic but weak scabicide
- useful for post treatment itch
- apply 2-3 times daily
- not recommended in pregnancy or lactation
What products can be used to treat the scabies itch? (5 points)
- crotamiton
- calamine lotion (may be drying) calamine cream
- pinetarsol bath, or diluted as dab on lotion
- topical CS (but only after scabicide is used, do not use on infested areas)
- oral antihistamine (sedating helps with sleeping)
When should scabies be referred? (4 points)
- presence of secondary bacterial infection
- rash does not respond at all to treatment (no decrease in itch 5 or more days after treatment)
- resistance (live mites present even after appropriate treatment used)
- uncertainty about diagnosis
What are the two main types of fungal/yeast infections?
- Candida albicans (topical yeast infections)
- tinea infections
What are the main characteristics of topical yeast infections? (5 points)
- red and scaly
- poorly defined border
- may have scattered satellite pustules outside main rash area
- often assoc. with immunodeficiency and diabetes
- usually located in warm moist areas such as skin creases
What are the common sites of topical yeast infections? (5 points)
- groin
- nail fold
- under breasts
- between buttocks
- between toes
“Warm moist areas”
What are three main classes of dermatophytes that cause tinea infections ?
- trichophyton
- microsporon
- epidermophyton
What are the main areas involved with tinea infections? (3 points)
Hair, skin and nails
What are the main types of tinea infections? (5 points)
- corporis (body)
- capitus (head)
- cruris (groin)
- pedis (feet)
- ungium (nails)
What are the main char actuaries of tinea corporis? (6 points)
- affects the body e.g. Ringworm
- spreading circular red lesions
- rings can join together
- scaling at leading edge of lesion
- mild itch
- hair loss within lesion area
What are the main characteristics of tinea capitus? (4 points)
- affects the head
- spreading circular red lesions
- scaling scalp
- hair loss e.g. Broken off, or stubble
What are the main characteristics of Texan cruris? (5 points)
- affects groin e.g. Joggers itchy, jock itch, crotch rot.
- very itchy, red spreading lesions
- pimple like eruptions
- marked red border at leading edge of lesion
- may spread to buttocks
What are the main characteristics of tinea pedis? (5 points)
- affects the feet e,g, atheletes foot
- mild redness with some scaling and peeling
- may be macerated my weeping, bad smell (due to yeast, bacteria)
- itch or burning sensation
- often between the toes or soles/sides of feet
What are the main characteristics of tinea ungium? (3 points)
- affects the nails
- often associated with tinea of the skin
- associated with crumbling, yellow nails.
What are the main principles of fungal infection treatment ? (5 points)
- dry area thoroughly (saline soaks 3-4x/day to dry weeping areas)
- most antifungals are applied once or twice daily and continued 1-2 weeks after infection has cleared
- dry up wet areas with powder, gel or lotion
- moisturise dry areas with creams and ointments (strengthen skin barrier)
- do not use hydrocortisone unless combined with effective anti-fungal
Why should hydrocortisone not be used alone in fungal skin infections? (2 points)
- hydrocortisone does not treat the infection
- it may reduce the immune response and encourage infection spread which causes strange and paler patterns known as tinea incognito
How can fungal infections of the feet be prevented? (5 points)
- keep areas dry, esp. Between ties
- wear cotton socks (not nylon or acrylic)
- avoid plastic or rubber shoes
- don’t walk barefoot in public showers
- use antifungal powder or spray to dust shows and feet
How can fungal infections of the groin be prevented? (3 points)
- wear cotton underwear
- avoid wearing nylon next to the skin e.g. Pantyhose, underwear)
- keep skin dry e.g. Neat feet range, products containing antiperspirants prevent swearing and chafing in these areas.
What are the different dosage forms available to treat fungal/yeast infections? (7 points)
- solutions
- creams
- lotions
- ointments
- gels
- powders
- sprays
What are antifungal solutions suitable for? (3 points)
- inflamed and moist areas
- they have a cooling effect, especially between toes or hair areas
- be careful with alcoholic vehicles as they may sting
What are antifungal creams suitable for? (2 points)
- general body surfaces
- caution as they tend to run when applied to weeping areas
What are antifungal lotions suitable for? (3 points)
- hairy and weeping areas
- also suitable for inflamed and moist areas due to cooling effect
- caution with alcoholic vehicles as they may sting
What are antifungal ointment suitable for?
-dry, Scaly lesions
What are antifungal gels suitable for?
-hairy areas
What are antifungal powders suitable for? (2 points)
- flexural areas and in between the toes to absorb moisture
- can be used once infection has cleared to dust skin and shows as a preventative
What are antifungal sprays suitable for? (5 points)
- all kinds of surfaces EXCEPT sensitive genital areas
- can be used once infection has cleared to dust skin and shoes as a preventative
- powder has good staying power on skin
- as it is a non-contact delivery devices it can be used on many people due to no cross contamination
- good for hard to reach areas and skin folds
Which medications are used to treat fungal infections? (5 points)
- imidazoles
- terbinafine
- ciclopiroxolamine
- undecylenic acids, benzoic acids, salicylic acids
- gentian violet, castellani’s paint
What are the imidazoles? (5 points)
- fungalstatic drugs such as clotrimazole, Miconazole, econazole, ketonconazole, tioconazole
- active against candida and G+ bacteria
- almost no systemic absorption
- 70-100% cure rate
- apply bd and 14 days after clearing
What is terbinafine? (6 points)
- fungalcidic drug e,g, allymine antifungal
- active against some yeasts
- apply bd for 1-2 weeks and another week after clearing
- good skin penetration within 3 days, acts more rapidly than imidazoles to eradicate dermatophytes.
- dermatophytes may be killed before skin has healed completely
- also available as lamisil once but data on clearance rate not clear.
What is ciclopiroxolamine ? (3 points)
- broad spectrum antifungal and antibacterial
- use bd and 14 days after clearing
- available as nail lacquer to treat nail fungal infections
What are the undecylenic acids, benzoic acids, salicylic acids? (2 points)
- not active against candida or bacteria
- requires continual treatment 4 weeks after lesions have cleared
What is gentian violet and castellani’s paint? (3 points)
- old remedies for fungal skiing infections
- gentian violet is rx only
- stains clothing, messy to use and not recommended due to mutagenic activity
