TIPS FOR DIAGNOSIS
Careful history and physical examination must be performed.
Skin biopsy, hair light microscopy, and genetic testing can be used to rule out differential diagnoses.
Silvery hair syndrome subtypes can often be determined with simple hair light microscopy.
Many conditions have similar presentation in hair color change such as piebaldism and Waardenburg syndrome; differential diagnosis relies on associated clinical findings.
PATIENT EDUCATION POINTS
The onset of hair graying as a result of aging is dependent on genetics and environmental factors.
Oxidative stress accelerates hair graying and should be addressed.
There is currently no definitive treatment to reverse hair hypopigmentation.
Hair color change occurs naturally as part of the aging process, presenting as graying of the hair and can also present as a clinical feature in a number of diseases. This chapter aims to inform the clinician of the potential underlying disease processes and conditions in which hair hypopigmentation, repigmentation, or discoloration have been observed as well as clues for diagnosis and treatment.
Changes in hair color affect all ethnicities and sexes. Epidemiology of specific conditions will be described in this chapter in the “Clinical Features” section.
Melanogenesis of the hair follicle differs from the skin in that pigment production is cyclic. It follows the stages of the hair cycle, where hair pigmentation is active during the anagen phase, turned off during the catagen phase, and is absent during the telogen phase.1,2 The etiology and pathogenesis of hair hypopigmentation are not fully understood as it can occur as part of natural aging, due to premature aging diseases, autoimmune diseases, and extrinsic factors such as oxidative stress.3 Targeting a single mechanism that controls hair pigmentation may not be sufficient in reversing changes in hair color due to the complexity of the regulatory processes of melanogenesis. Studying the process of natural hair hypopigmentation assists in our understanding of human aging. Currently, no direct treatments have been found to reverse or halt this process, even though antioxidants can potentially slow the process.
Hair graying, also called achromotrichia or canities, is a mixture of pigmented and depigmented hair follicles and it occurs ...