It can be unsettling to consider that microscopic organisms might be living in our hair. While the thought of “hair bugs” can cause discomfort, many common inhabitants are identifiable and treatable. This article explores these tiny residents and how to manage them.
Primary Hair Dwellers: Lice
Three main types of human lice can inhabit different areas of the body, including hair. Head lice, scientifically known as Pediculus humanus capitis, are tiny, wingless insects, light brown and about the size of a sesame seed when adult. They primarily reside on the scalp, behind the ears, and at the nape of the neck, feeding on human blood. Head lice eggs, called nits, are often found cemented to hair shafts close to the scalp, appearing as tiny yellow, tan, or brown dots. Transmission most commonly occurs through direct head-to-head contact, though sharing personal items like hats, scarves, or combs can also spread them.
Body lice, Pediculus humanus humanus, differ from head lice, primarily living in clothing and bedding and moving to the skin only to feed. They are associated with poor hygiene or crowded environments where individuals lack access to clean clothing and regular bathing. Body lice can transmit diseases such as epidemic typhus, trench fever, and relapsing fever.
Pubic lice, or Pthirus pubis, often called “crabs” due to their crab-like appearance, are found in coarser body hair. This includes the genital area, eyebrows, eyelashes, beards, and armpit hair. Pubic lice are primarily transmitted through sexual contact.
Microscopic Inhabitants: Mites
Beyond lice, microscopic mites can also inhabit human hair follicles, with Demodex mites being the most common. Two primary species found on humans are Demodex folliculorum and Demodex brevis. These tiny, eight-legged arachnids are nearly transparent and range from 0.15 to 0.4 millimeters in length, making them invisible to the naked eye.
Demodex folliculorum lives within hair follicles, especially on the face, consuming skin cells. Demodex brevis resides deeper within sebaceous glands connected to hair follicles, feeding on sebum, the skin’s natural oil. These mites are naturally occurring on almost everyone’s skin and do not cause issues. However, an overpopulation of Demodex mites can lead to skin conditions like demodicosis, presenting with redness, itching, or rosacea-like symptoms.
Identifying and Addressing Infestations
Recognizing a hair bug infestation often begins with common symptoms, such as persistent itching, particularly on the scalp, neck, or around the ears. A crawling sensation on the scalp or the presence of small red bumps or sores from scratching can also indicate an issue. Visual inspection is a reliable method for identification, focusing on the scalp, behind the ears, and the nape of the neck for head lice. Nits, which are lice eggs, are often easier to spot than adult lice, as they are firmly attached to the hair shaft and do not easily brush off like dandruff.
Infestations occur through direct person-to-person contact, such as head-to-head contact for head lice. Sharing personal items like combs, brushes, hats, or bedding can also facilitate transmission. To manage infestations, common approaches include using over-the-counter or prescription medicated shampoos and lotions designed to kill lice and their eggs. Manual removal through wet combing with a fine-toothed nit comb is also effective, especially when combined with conditioner to help the lice and nits adhere to the comb.
Cleaning and disinfecting personal items, including clothing, bedding, and hair accessories, is an important step in preventing reinfestation. To prevent future infestations, it is advisable to avoid head-to-head contact and refrain from sharing personal items like combs, hats, and towels. Regularly checking hair, especially in children, can help detect infestations early. If home treatments are ineffective, symptoms worsen, or there is uncertainty about the diagnosis, consulting a doctor or pharmacist for further guidance is recommended.