What causes lice in pregnant women? - briefly
Head‑to‑head contact, sharing combs, hats, bedding, or living in crowded conditions introduces Pediculus humanus capitis, the same parasite that affects the general population. Hormonal and immune changes during pregnancy can increase scalp oiliness, making the environment more conducive to infestation.
What causes lice in pregnant women? - in detail
Pregnant individuals are susceptible to head‑lice (Pediculus humanus capitis) infestations for several physiological and behavioral reasons.
Hormonal fluctuations increase sebum production, creating a richer environment for lice to cling to hair shafts. Elevated levels of estrogen and progesterone also alter scalp temperature and moisture, conditions that favor egg (nit) attachment and hatch rates.
Immune modulation during gestation reduces the efficiency of the body’s innate defenses. The shift toward a Th2‑dominant response diminishes the activity of neutrophils and macrophages that would normally help limit ectoparasite colonization.
Physical changes such as hair thickening or lengthening, common in the third trimester, provide more surface area for lice to move and lay eggs.
Social and environmental factors contribute as well. Close contact with family members, especially children who are frequent carriers, raises the probability of transmission. Shared items—combs, hats, pillows, or bedding—serve as vectors when not properly disinfected.
Additional contributors include:
- Reduced personal hygiene due to fatigue or nausea, leading to infrequent washing of hair and bedding.
- Use of hair products that increase scalp oiliness, inadvertently creating a more attractive habitat.
- Limited access to over‑the‑counter lice treatments, as many medications are contraindicated or require physician approval during pregnancy.
Understanding these interrelated biological, immunological, and environmental elements helps explain why lice infestations can occur more readily in pregnant individuals. Prompt identification and safe management are essential to prevent secondary skin irritation and secondary bacterial infection.