B85.3 Phthiriasis

Name of the Condition

• Phthiriasis

Summary

Phthiriasis is a parasitic infestation caused by pubic lice (Phthirus pubis), small, wingless insects that feed on human blood. This condition is highly contagious and spreads primarily through direct contact or shared personal items. Infestations typically present with itching and visible lice or nits (lice eggs) in the pubic area, though some individuals may be asymptomatic.

Causes

The infestation is caused by pubic lice (Phthirus pubis), which are transmitted through close personal contact, including sexual activity, or indirectly via shared items like clothing, bedding, or towels. Lice cannot jump or fly but crawl between hosts. The condition is not related to personal hygiene and can affect individuals of any age or background.

Risk Factors

• Close contact with an infested individual, such as through sexual activity or shared personal items.
• Sharing clothing, bedding, or towels with an infested person.
• Living in crowded conditions where personal items are frequently shared.

Symptoms

• Intense itching in the pubic area, often worse at night.
• Visible lice or nits (small, oval eggs) attached to pubic hair.
• Skin irritation or redness in the affected region.

Diagnosis

Diagnosis is typically made by visual inspection of the pubic area for lice or nits. Healthcare providers may use a magnifying glass or comb to identify the parasites. In some cases, a sample of hair or skin may be examined under a microscope to confirm the presence of lice or eggs.

Treatment Options

Treatment involves topical or oral medications to kill lice and nits. Common options include permethrin cream, pyrethrin shampoo, or oral ivermectin. It is important to treat all close contacts and wash or dry-clean infested clothing, bedding, and towels to prevent reinfestation. Follow-up may be recommended to ensure the infestation is resolved.

Prognosis and Follow-Up

With proper treatment, the prognosis is excellent, and most infestations resolve within 1-2 weeks. Follow-up may be necessary to confirm eradication and check for reinfestation. Recurrence is possible if close contacts or shared items are not treated.

Complications

Complications are rare but may include secondary bacterial infections from scratching, skin irritation, or allergic reactions to lice bites. In severe cases, intense itching can lead to sleep disturbances or anxiety.

Lifestyle & Prevention

• Avoid sharing clothing, bedding, or towels with others.
• Practice safe sex and limit the number of sexual partners to reduce transmission risk.
• Regularly wash and dry-clean personal items, especially after potential exposure.
• Educate household members or close contacts about the importance of treatment and prevention.

When to Seek Professional Help

Seek medical attention if itching persists after treatment, if symptoms worsen, or if you suspect a secondary infection (e.g., increased redness, pus, or fever). Consult a healthcare provider if you are unsure about diagnosis or treatment options.

Tips for Medical Coders

When coding for phthiriasis (B85.3), ensure documentation specifies the presence of pubic lice (Phthirus pubis) and any associated symptoms or treatments. Note the anatomical location (pubic area) and confirm the absence of other lice infestations (e.g., head or body lice) to avoid miscoding. Include details about transmission risk factors or complications if present, as these may impact coding specificity.