B85 Pediculosis and phthiriasis

Name of the Condition

• Pediculosis and phthiriasis

Summary

Pediculosis and phthiriasis are parasitic infestations caused by lice, which are small, wingless insects that feed on human blood. Pediculosis refers to infestations by head lice (Pediculus humanus capitis), body lice (Pediculus humanus corporis), or pubic lice (Phthirus pubis), while phthiriasis specifically denotes pubic lice infestation. These conditions are highly contagious and spread through direct contact or shared personal items. Infestations typically present with itching and visible lice or nits (lice eggs) on the affected area.

Causes

The infestations are caused by three types of lice: head lice, body lice, and pubic lice. Head lice and body lice belong to the species Pediculus humanus, while pubic lice are Phthirus pubis. Transmission occurs through close personal contact, sharing of combs, hats, or clothing, or sexual contact (for pubic lice). Lice cannot jump or fly but crawl between hosts. Body lice are often associated with poor hygiene or crowded living conditions, while head and pubic lice can affect anyone regardless of cleanliness.

Risk Factors

• Close contact with an infested individual, such as in households, schools, or daycare settings.
• Sharing personal items like combs, brushes, hats, or bedding.
• Sexual activity, which increases the risk of pubic lice transmission.
• Crowded or unsanitary living conditions, which facilitate body lice spread.
• Lack of regular hair washing or grooming, though head lice can infest clean hair.

Symptoms

• Intense itching (pruritus) at the site of infestation, often worsening at night.
• Visible lice or nits attached to hair shafts, especially near the scalp, body, or pubic area.
• Small red bumps or sores from scratching, which may become infected.
• For pubic lice, blue-gray spots (maculae ceruleae) on the skin or underwear.
• For body lice, possible fever or fatigue in severe infestations.

Diagnosis

Diagnosis is typically made by visual inspection of the affected area for lice or nits. A healthcare provider may use a magnifying glass or comb to detect the parasites. Nits are often easier to spot than live lice, as they adhere firmly to hair shafts. In some cases, a skin scraping may be examined under a microscope to confirm the presence of lice or their eggs. Diagnosis is straightforward when live lice or viable nits are identified.

Treatment Options

Treatment involves topical or oral medications to kill lice and nits. Over-the-counter or prescription shampoos, lotions, or creams containing permethrin, pyrethrin, or ivermectin are commonly used. For resistant cases, oral ivermectin may be prescribed. It is essential to treat all close contacts and thoroughly clean bedding, clothing, and personal items to prevent reinfestation. Nit removal with a fine-toothed comb is often recommended to ensure complete eradication.

Prognosis and Follow-Up

With proper treatment, the prognosis is excellent, and infestations resolve within 1–2 weeks. Follow-up is generally not required unless symptoms persist or reinfestation occurs. Itching may continue for a few days after treatment due to allergic reactions to lice bites. Reinfection is common if close contacts or shared items are not treated. Good hygiene and regular checks can help prevent recurrence.

Complications

Complications are rare but may include secondary bacterial infections from scratching, such as impetigo or cellulitis. In severe cases, body lice infestations can lead to systemic reactions like fever or fatigue. Pubic lice infestations may cause psychological distress due to their association with sexual activity. Allergic reactions to lice bites can also occur, leading to intense itching or swelling.

Lifestyle & Prevention

Prevention involves avoiding direct contact with infested individuals and not sharing personal items like combs, hats, or clothing. Regularly washing bedding and clothing in hot water and drying on high heat can kill lice and nits. For head lice, avoiding head-to-head contact and keeping hair tied back may reduce risk. Good personal hygiene, including regular bathing and hair washing, can help minimize infestations, though lice do not discriminate based on cleanliness.

When to Seek Professional Help

Seek medical attention if itching persists after treatment, if there are signs of infection (e.g., pus, redness, swelling), or if reinfestation occurs. A healthcare provider should evaluate cases where over-the-counter treatments fail or if the infestation is severe. Pregnant individuals or those with open sores should consult a doctor before using certain medications.

Tips for Medical Coders

When coding for pediculosis and phthiriasis, use code B85 to represent the condition. Documentation should specify the type of lice (head, body, or pubic) if known, as this may impact treatment and follow-up. Ensure the code is assigned based on clinical findings, such as visual identification of lice or nits. Avoid using this code for related conditions like scabies or other ectoparasitic infestations. Verify that the code aligns with the provider’s diagnosis and treatment plan for accurate reporting.