Scabies is a skin infestation caused by the microscopic mite Sarcoptes scabiei var. hominis, which burrows into the outer layer of human skin. While commonly affecting areas like fingers, wrists, elbows, and genitals, scabies can also affect the scalp. Though less common, understanding scalp involvement is important for identification and management. This article explores scalp scabies conditions, symptoms, diagnosis, treatment, and prevention.
When Scabies Affects the Scalp
Scalp involvement in scabies typically occurs in specific circumstances, such as crusted scabies (Norwegian scabies). This severe form involves millions of mites and often extends to the scalp, face, and nails, appearing as thick crusts and scales. Crusted scabies is more prevalent in individuals with weakened immune systems (e.g., HIV/AIDS, organ transplant recipients, immunosuppressive medications), the elderly, or those with certain neurological or mental impairments.
Infants and young children can also experience scalp scabies. Their immature immune systems and thinner skin make them vulnerable to widespread infestations, including the head, neck, palms, and soles of the feet, areas rarely affected in adults.
Identifying Scalp Scabies Symptoms
Recognizing scalp scabies is challenging due to hair obscuring typical skin lesions. Intense itching is a hallmark symptom, often worsening at night or after a hot bath as warmth stimulates mite activity. This constant itching can lead to discomfort and sleep disturbances.
The scalp rash may appear as small, red bumps (resembling pimples) or scaly, crusted patches. Mite burrows, though characteristic, are difficult to visualize due to hair. Persistent scratching can break the skin, leading to secondary bacterial infections like sores, pus, or impetigo-like lesions. Severe or chronic cases may disrupt hair follicles, causing temporary hair loss. Lesions might also extend to the hairline, neck, or behind the ears.
Diagnosing and Treating Scalp Scabies
Diagnosing scalp scabies involves a medical professional examining the skin for characteristic lesions. Visual inspection may be followed by a skin scraping. This procedure involves gently scraping skin from an affected area and examining it under a microscope to identify mites, eggs, or fecal matter (scybala). Though challenging due to hair, microscopic confirmation is the most reliable diagnosis.
Treatment aims to eliminate mites and their eggs. Topical medications, primarily permethrin 5% cream, are the main treatment. For scalp involvement, the cream must be applied thoroughly to the entire scalp, and sometimes to the face and neck, depending on infestation extent. It is typically left on for 8 to 14 hours before washing, with a second application recommended after a week.
Oral medications, such as ivermectin, are often used for crusted or widespread scalp infestations, especially when topical treatments are difficult or have failed. Antihistamines can alleviate itching, and antibiotics may treat secondary bacterial infections from scratching. All household members and close contacts usually require simultaneous treatment to prevent re-infestation.
Preventing Scabies Spread
Preventing scabies spread, particularly with scalp involvement, requires eliminating mites from the infected person and their environment. Avoiding direct skin-to-skin contact is crucial, as it’s the primary transmission mode. Since mites survive off the body for 48-72 hours, environmental decontamination is also important.
All clothing, bedding, and towels used by the infested person and close contacts within 72 hours should be washed in hot water (at least 120°F or 50°C) and dried on a hot cycle. Unwashable items, like stuffed animals, can be sealed in plastic bags for 72 hours to a week to deprive mites of a host. Simultaneous treatment of all household members and close contacts, even if asymptomatic, helps break the re-infestation cycle and eradicate mites.