17 - Pinworms Flashcards
What are pinworms?
Intestinal infection due to Enterobius vermicularis
Which species are hosts for pinworms?
Only humans (not transmitted through animal feces)
What is the role of animals in pinworm infestation?
Pinworm eggs can get on animal fur, and then a human can pet the animal and if they put their hand to mouth w/o washing it, can ingest the eggs and become infected
What is the pathophysiology of pinworms?
- Human ingests mature pinworm eggs; ova reaches stomach and outer coating is dissolved to release larvae; larvae hatch in duodenum and mature over 1-2 months
- Live and mate throughout large intestine attached to mucosa
- At night, pregnant females exit anus to lay eggs, leaving about 10,000 ova on perianal skin
- After laying eggs, females usually die (but can re-enter the individual)
- Ova become infective w/in 6 hours of being deposited and remain infective for up to 14-20 days
- Ova have sticky outer layer, allowing them to stick to various surfaces
What are the methods of transmission for pinworms?
- Finger to mouth (swallowed)
- Inhalation
- Retroinfection
What are risk factors for pinworms?
- Overcrowded living conditions
- Children 5-10 y/o (uncommon in children under 2 y/o)
- Temperate and cold climates
What are the signs and symptoms of pinworms?
- Can be asymptomatic
- Perianal or perineal itching (worse at night)
- Insomnia, irritability, restlessness
- Major infestations may cause abdominal pain, anorexia, or diarrhea
- Less common = urinary tract and vaginal sx
What are red flags for pinworms?
- Must have diagnosis before treatment (esp. if pregnant, under 12 y/o, and have renal or hepatic dysfunction)
- Abdominal pain
- Severe diarrhea
- Bloody bowel movement or painful urination
- Fever
- Extremely poor appetite
- Self-inflicted lesions from repetitive scratching
- Suspect sexual abuse
What are the 3 ways to diagnose pinworms?
1) Inspection of perianal area – 1 hour after child falls asleep, visually examine anus w/ flashlight to observe worms
2) Scotch-tape test – first thing in the morning, press a piece of tape on perianal skin, then stick to glass slide; may be repeated several times
3) Microscopic evaluation of subungual sample (under fingernails)
What are the goals of treatment for pinworms?
- Eradicate pinworms from px and household
- Eliminate symptoms
- Promote good hygiene
- Prevent reinfection and transmission
How can pinworms be prevented?
- Handwashing after using toilet, after scratching perianal area, and before and after eating/preparing food
- Keep nails short and discourage nail biting
What are some non-pharms to recommend for pinworms?
- Shower every morning
- Wash bed sheets, towels, and underwear in hot water daily for 2 weeks
- Wash hands and clean fingernails frequently
- All family members should wear cotton underwear during day and night and change twice daily (for 1 week after tx)
Who should be treated for pinworms?
Infested individual and all household members/close contacts (unless contraindication for medication)
What is the OTC treatment for pinworms? What schedule is it and why?
- Pyrantel pamoate
- Schedule 2 b/c family members need to be treated after 1 diagnosis has been made
What is the MOA of pyrantel pamoate in patient friendly language?
Paralyzes the pinworms, so they no longer stick to intestinal wall and then are carried out of the patient in the stool
