Terminal hair is the thick, long, pigmented hair found on the scalp, eyebrows, and other body areas. When it appears “scant,” it means it is sparse, thin, or reduced in density.
The Nature of Terminal Hair
Terminal hair is characterized by its coarse texture, darker pigmentation, and longer growth phase. It is found on the scalp, eyebrows, eyelashes, and develops in areas like the pubic region and armpits after puberty. Increased androgen levels can transform fine, unpigmented vellus hair (often called “peach fuzz”) into thicker terminal hair on the face, chest, and limbs.
The growth of terminal hair follows a cyclical pattern. The anagen phase is the active growth period, lasting two to eight years for scalp hair. The catagen phase is a short transitional period where follicles shrink and growth slows. The telogen phase is a resting period of two to four months, after which hair sheds and the cycle restarts.
Underlying Reasons for Scantness
Several factors can contribute to scant terminal hair by affecting the hair growth cycle or follicles. Genetic predisposition is a common cause, particularly in conditions like androgenetic alopecia, known as male or female pattern baldness. In this hereditary condition, hair follicles on the scalp gradually shrink due to dihydrotestosterone (DHT), leading to shorter, finer, and less pigmented hair.
Hormonal imbalances can also play a role in hair thinning. Thyroid issues, whether overactive or underactive, can disrupt the hair growth cycle, causing widespread hair loss. Polycystic Ovary Syndrome (PCOS) in women, characterized by elevated androgen levels, may lead to hair thinning on the scalp while also causing increased hair growth in other areas. Certain medical conditions, such as alopecia areata, involve the immune system mistakenly attacking hair follicles, resulting in patchy hair loss.
Nutritional deficiencies can impact hair health, with insufficient levels of iron or zinc potentially contributing to scant hair. Chronic illnesses and significant physiological stress can push hair follicles into the resting phase prematurely, leading to increased shedding. Additionally, some medications and tight hairstyles that consistently pull on hair, known as traction alopecia, can cause localized or generalized hair thinning.
Identifying the Cause
If you notice scant terminal hair, seeking professional medical advice is recommended. A dermatologist, a physician specializing in skin and hair conditions, can accurately diagnose the underlying cause. The diagnostic process typically begins with a thorough medical history review, including questions about the onset and pattern of hair loss, family history, diet, and hair care routines.
A physical examination of the scalp allows the dermatologist to check for inflammation, redness, or scarring, and to assess the pattern and extent of hair loss. Specialized tests may be conducted, such as a hair pull test, where a small section of hair is gently tugged to determine the number of shedding hairs. If more than a certain percentage of hairs come out, it can indicate active hair loss.
Blood tests are often ordered to check for medical conditions, vitamin deficiencies, or hormonal imbalances that might be contributing to hair loss. These tests may include checking ferritin levels for iron stores, thyroid function, and hormone levels.
In some cases, a scalp biopsy, which involves taking a small tissue sample from the scalp for microscopic examination, can provide detailed information about hair follicle health and identify specific conditions.
Approaches to Management
Managing scant terminal hair involves addressing the underlying cause. For androgenetic alopecia, topical minoxidil can stimulate hair growth by increasing blood flow to hair follicles and prolonging the anagen phase. Oral finasteride may also be prescribed for male pattern baldness to reduce the effects of DHT on hair follicles.
Inflammatory conditions like alopecia areata may be treated with corticosteroids, administered topically, orally, or via injections, to suppress the immune response attacking hair follicles. If hormonal imbalances are identified, such as thyroid dysfunction or PCOS, treatments aimed at restoring hormonal balance can help improve hair density.
Nutritional deficiencies are addressed through dietary improvements or supplements, ensuring adequate intake of essential vitamins and minerals like iron and zinc. Lifestyle adjustments, including stress management techniques, can be beneficial, as severe stress can contribute to hair shedding.
Cosmetic solutions offer temporary coverage for thinning areas; these include hair fibers made of keratin protein that cling to existing hair to create a fuller appearance. Wigs and hair toppers provide more comprehensive coverage. For some individuals, hair transplant surgery, where hair follicles are moved from denser areas to thinning or bald spots, can offer a more permanent solution.