Pinworm Infection: Symptoms and Clinical Presentation
The most common symptom of pinworm infection is nocturnal perianal itching, though 30-40% of infected children remain completely asymptomatic. 1
Primary Clinical Features
Classic Presentation
- Nocturnal perianal pruritus is the hallmark symptom, occurring when female worms migrate to lay eggs around the anus at night 1, 2
- The itching is characteristically worse at night and can cause significant sleep disturbance and mental distress 2, 3
Additional Symptoms in Children
- Gastrointestinal symptoms: abdominal pain, diarrhea 1
- Behavioral changes: irritability, restlessness 1
- Weight loss in some cases 1
- Vaginal discharge in girls due to female genital tract colonization when worms migrate into the vaginal area 1, 4
Asymptomatic Infections
- Approximately 30-40% of infected patients show no clinical symptoms whatsoever, making diagnosis challenging in these cases 1, 2
- These asymptomatic carriers can still transmit infection to household members 2
Epidemiology and Risk Factors
High-Risk Populations
- Children aged 5-14 years have the highest prevalence, with estimates of 2-20% in Germany and up to 60% in some developing countries 2, 3
- Infants under 2 years and adolescents over 14 years are only sporadically affected 3
Key Risk Factors
- Behavioral factors: nail-biting (onychophagia), uncontrolled anus-finger-mouth contact, finger-sucking 3
- Environmental factors: poor personal hygiene, overcrowding, inadequate sanitation, poor socioeconomic conditions 2
- Household exposure: living with young children or recently arrived immigrants from developing countries 4
Diagnostic Approach
Cellophane Tape Test (Gold Standard)
- Apply the sticky side of clear tape to the perianal skin first thing in the morning before bathing or bowel movements 1
- A single test has approximately 50% sensitivity, but performing the test on three consecutive mornings increases sensitivity to approximately 90% 2
- This is the preferred diagnostic method because pinworms and eggs are not usually passed in stool 1
Visual Identification
- Adult worms may be visible in the perianal area or occasionally in stool, appearing as small white thread-like organisms 2
- Pathological examination of a visualized worm provides definitive diagnosis 2
When Stool Examination is NOT Recommended
- Standard stool microscopy is not useful for pinworm diagnosis since eggs and worms are rarely found in feces 1, 2