B85.0 Pediculosis due to Pediculus humanus capitis

Name of the Condition

• Pediculosis due to Pediculus humanus capitis

Summary

Pediculosis due to Pediculus humanus capitis, commonly known as head lice infestation, is a parasitic condition caused by the head louse (Pediculus humanus capitis). This infestation is characterized by the presence of lice and their eggs (nits) on the scalp and hair shafts. It is highly contagious and spreads primarily through direct head-to-head contact or shared personal items like combs, hats, or bedding. Infestations typically present with intense scalp itching, though some individuals may be asymptomatic.

Causes

The condition is caused by the head louse (Pediculus humanus capitis), a small, wingless insect that feeds on human blood. Transmission occurs through close personal contact, such as head-to-head interaction, or indirectly via shared items like hairbrushes, hats, or bedding. Lice cannot jump or fly but crawl between hosts. The infestation is not related to personal hygiene and can affect individuals of any age or socioeconomic background.

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.
• Crowded living conditions or frequent group activities where head contact is common.

Symptoms

• Intense scalp itching, often worse behind the ears or at the nape of the neck.
• Visible lice or nits (small, oval-shaped eggs) attached to hair shafts, typically within 1 cm of the scalp.
• Irritability or difficulty sleeping due to itching.

Diagnosis

Diagnosis is typically made through visual inspection of the scalp and hair for live lice or nits. A magnifying glass or fine-toothed comb may aid in detection. Nits are often confused with dandruff or hair debris, so confirmation of live lice or viable nits is key. In some cases, a healthcare provider may use a dermoscope or microscopic examination to confirm the presence of lice or nits.

Treatment Options

Treatment involves both killing the lice and removing nits. Over-the-counter or prescription pediculicides (lice-killing medications) are commonly used, applied according to label instructions. Manual removal of nits with a fine-toothed comb is recommended to prevent reinfestation. Household members and close contacts should be checked and treated if infested. Bedding, clothing, and personal items should be washed in hot water or dried on high heat to eliminate lice and nits.

Prognosis and Follow-Up

With proper treatment, the prognosis is excellent, and most infestations resolve within 1–2 weeks. Follow-up is important to ensure all lice and nits are removed, as incomplete treatment can lead to reinfestation. Itching may persist for a few days after treatment due to allergic reactions to lice saliva. Rechecking the scalp 7–10 days after treatment is advised to confirm eradication.

Complications

• Secondary bacterial skin infections from scratching, leading to impetigo or cellulitis.
• Allergic reactions to lice saliva, causing persistent itching or rash.
• Social stigma or psychological distress, particularly in children.

Lifestyle & Prevention

• Avoid sharing personal items like combs, hats, or bedding.
• Regularly check household members for signs of infestation, especially after exposure.
• Tie back long hair in school or group settings to reduce contact.
• Wash and dry bedding, clothing, and personal items on high heat to kill lice and nits.

When to Seek Professional Help

Seek medical attention if:

• Over-the-counter treatments fail to eliminate the infestation.
• There are signs of secondary infection, such as pus, swelling, or fever.
• The infestation is severe or widespread.
• You are unsure about proper treatment or need guidance on removal.

Tips for Medical Coders

When coding for pediculosis due to Pediculus humanus capitis, use ICD-10-CM code B85.0. Documentation should specify the presence of live lice or nits, as well as any associated symptoms or complications. Ensure the code is linked to the appropriate encounter type and that treatment details (e.g., pediculicides, manual removal) are clearly recorded. Avoid using this code for other lice infestations (e.g., body or pubic lice), which have distinct codes.