Hair color is primarily under close genetic factors. Enzyme degradation products of melanosomes
within matrix cells may cross cell membranes to melanocytes and control further melanin production.
Follicular melanocytes are known to respond like epidermal melanocytes to melanocyte stimulating
hormone (MSH), which can darken light-colored hair.
Premature graying of hair has been defined as the onset of hair graying before 20 years of age in
Caucasoid and 30 years of age in Negroid. It probably has a genetic basis and occasionally occurs as
an isolated autosomal dominant condition.
Autoimmune diseases .
Pernicious anemia.
Book‘s syndrome: this is an autosomal dominant trait. The syndrome is characterized by :
Premature graying of hair.
Premolar hypodontia.
Palmoplantar hyperhidrosis.
Premature ageing syndromes: Progeria and Werner‘s syndrome .
In progeria it is associated with marked loss of scalp hair as early as 2 years of age.
Rothmund-Thomson syndrome.
Hereditary defects.
White spotting or partial albinism is an autosomal dominant
abnormality with patches of skin totally devoid of pigment, which
remain unchanged throughout life. Most commonly, a frontal white
patch occurs - the white forelock - which may be the only sign.
Fig. 429. Piebaldism
Syndromes associated with piebaldism
Tiez’s syndrome
Generalized ‘white spot‘.
Loss of skin and hair pigment.
Complete deaf mutism.
Waardenburg‘s syndrome
The Vogt-Koyanagi-Harada syndrome.
This syndrome is characterized by:
Alopecia areata.
Bilateral uveitis.
Labyrinthine deafness.
Tinitus, vitiligo and poliosis
Alezzandrini‘s syndrome
Unilateral facial vitiligo.
Poliosis of eyebrows and eyelashes .
Perceptive deafness is rarely associated.
Tuberose sclerosis
Depigmented hair may be the earliest sign .
Von Recklinghausen‘s disease
Multiple neuro fibromatosis: café au lait macules, axillary, perineal freckling, and cystic lesions.
Nutritional deficiencies
In protein malnutrition, such as in kwashiorkor, hair color changes which are prominent features.
Normal black hair becomes brown or reddish, and brown hair becomes blonde.
Severe iron-deficiency anemia.
White hair may occur in vitamin B12 deficiency.
Metabolic disorders
Severe ulcerative colitis and after extensive bowel resection.
Phenylketonuria :Black hair may become brown.,
Accidental hair discoloration
Exposure to high concentrates of copper in industry or from inadvertently high concentrations in tap
water or in swimming pools may cause green hair, particularly visible in blonde-haired subjects.
Picric acid and Dithranol may cause yellowish hair.
Hair cosmetics
Soaps and shampoos are made from vegetable or animal fats that can remove dirt and greases as
efficiently as detergents . The ingredients contained in the shampoos such as tar and many others
may cause change of the hair color.
Straightening gels and fixatives of the hair may have also the same effect.