Approach to the Patient with Hair Growth Disorders at a Glance
- Take patient with hair growth disorders serious and provide emotional support.
- Classify hair disorder based on patient's history and clinical pattern (see eTable 88-0.2).
- Exclude or confirm common hair growth disorders based on clinical assessment and diagnostic tools (see Table 88-1).
- Find the right treatment for confirmed diagnosis.
- Dispel misconceptions on treatment options and results, and educate patient.
The importance of human hair in view of social communication and sexual attraction is enormous. Thus, diseases that lead to hair loss (alopecia), structural hair shaft defects or excessive hair growth on the body are often accompanied by diminished sense of personal well-being and self-esteem, leading to depressive moods and withdrawal from social interims.
In this chapter, we discuss the biologic basis and clinical presentation of hair growth disorders, give definitions (eTable 88-0.1), explain key management principles, and provide practical advice for diagnosis, therapy and patient management.
eTable 88-0.1 Definitions |Favorite Table|Download (.pdf)
eTable 88-0.1 Definitions
Active process of hair shedding
Loss of hair, reduced hair density (scalp or body)
Large hair follicle with a thick, medullated hair shaft >30 μm, roots are located in the subcutaneous fat
Very small colorless non-medullated hair (<30 μm, roots are located in the upper dermis), only a few mm long. Vellus hairs can be found on the entire body except for palms and sols in different densities, depending on the body site.
Hair that evolves from a former terminal hair follicle that had been miniaturized (due to androgenetic alopecia or alopecia areata), very small colorless hair (<30 μm, roots are located in the dermis), fibrous tissue (fibrous streamer) replaces the former terminal follicle below the root down to the subcutaneous fat
Hair in a transition stage from terminal to vellus-like due to a miniaturization process (∼50–30 μm, roots are located in the deeper dermis)
First hair produced in utero, pigmented, around 2–3 cm long, lanugo hairs are usually shed between week 32–36 of gestation but can be still present at birth in one third of children
Growth of terminal hair on the body in a male distribution in women
Increased growth of terminal hair or growth of lanugo hair on the body in an androgen-independent pattern
Graying of hair
Sudden (over night) graying of hair, appears in diffuse alopecia areata, when white hairs are spared by the inflammation and remain on the scalp while dark hair falls out very quickly
Localized white hair
Irreversible hair loss, with loss of follicular ostia, and potentially skin atrophy
Life-long cyclic transformation of hair follicles, which begins in utero
Active growth phase, duration and growth rate depend on the body site (around 3–6 years on the scalp)
Resting period, the hair shaft does not grow longer; duration depends on the body site (around 3 months on the scalp)
Apoptosis driven regression phase between anagen and telogen
Process of hair shaft shedding
Hair with a pigmented root (except in white hair) and an inner root sheath (shows the form of a golf club ...