Scalp Hair Characteristics in the Newborn Infant

Susan A. Furdon, RNC, MS, NNP; David A. Clark, MD

Adv Neonatal Care. 2003;3(6)

Hair Growth and Loss

During late fetal and early neonatal life, synchronized cycles of hair growth and loss occur simultaneously. Anagen, or growing hair follicles, cover the entire scalp by about 18 to 20 weeks gestation. At 24 to 28 weeks gestation, the anagen hair follicles evolve to a short catagen phase in which the follicles involute.^[6] Telogen hair follicles are those in the final resting phase before the hair is shed as club hair (Fig 2).

(Enlarge Image)

Phases of the hair cycle. Anagen is the growing phase. Catagen is a short interphase prior to the resting phase, telogen. Hair is shed in the telogen phase as club hair. Reprinted with permission.[9]

In general, hair growth occurs from the forehead to the nape of the neck. At birth, there are 2 waves of scalp hair growth. The earliest wave of growth is the hair over the frontal and parietal regions of the scalp. This hair is already converting to telogen hair and will be shed first. The more recent wave is the anagen hair in the occipital region. This hair enters the telogen phase and is likely to fall out between 8 to 12 weeks after birth.^[9]

The density of hair follicles is highest at birth because of the cyclic stages of hair growth. Hair density, structure, and growth are correlated with sex, race, and nutritional status.^[7] Infants with darker complexions have a slower rate of transition to the telogen phase, so they tend to have more abundant hair at birth.^[10]

1 2 3 4 5 6 7

Next Section

Cite this: Scalp Hair Characteristics in the Newborn Infant - Medscape - Dec 01, 2003.

Abstract and Introduction
Hair Formation in Utero
Hair Growth and Loss
Hair Characteristics
Scalp Hair Examination
Abnormal Hair Findings
Implications for Clinical Practice
References
Sidebar: Internet Resources for Genetics

Table 1. Hair Terminology ^{[2,7,9,11,12]}
Term	Synonym	Definition
Alopecia	Baldness Hypotrichosis	Abnormal deficiency of hair; usually describes hair that is grown and then lost. Alopecia may be partial or complete, generalized or localized.
Anagen		First phase in hair cycle characterized by growth of hair follicles.
Catagen		Second phase in hair cycle. Short interphase between anagen and telogen hair phase, characterized by involution of the hair follicle.
Forelock		Lock of hair growing in the front of the head.
Hirsutism	Hypertrichosis	Condition characterized by excessive growth of hair. May be genetic, hormonal, or drug induced.
Hypotrichosis	Alopecia	Abnormal deficiency of hair. Usually describes lack of any hair growth.
Keratin		Protein substance in hair and nails.
Telogen		Third phase in hair cycle. Characterized as the resting phase of the hair follicle. Hair is shed as club hair.
Terminal hair		Thicker, more mature pigmented hair.
Vellus hair		Lighter pigmented, fine hair that may be present on the forehead and face.
Whorl		A pattern of hair growth characterized by a clockwise spiral or coil. Associated with the point of maximal brain growth.

Table 2. Racial Differences in Hair Characteristics ^[11]
	African American	Asian	Caucasian
Follicle density	100,000150,000 scalp follicles	90,000120,000 scalp follicles	100,000150,000 scalp follicles Follicle density related to hair color: (red < brown < blonde)
Follicle characteristics	More strength; more pliable	Coarse and thick	Thin
Presentation	Tightly coiled or spiral hair	Straight	Variable Straight, wavy, curly

Table 3. Syndromes Associated With Abnormal Hairlines ^[3]
Low Frontal Hairline Costello syndrome Cornelia de Lange syndrome Coffin-Siris syndrome Fanconi syndrome Fetal hydantoin syndrome
Atypical Hair Distribution Fraser syndrome (hair growth on lateral forehead extending to lateral eyebrow) Treacher Collins syndrome (projection of scalp hair onto lateral cheek)
Low Posterior Hairline Noonan syndrome Turner syndrome Kabuki makeup syndrome Cornelia de Lange syndrome Fetal hydantoin syndrome

Table 4. Abnormal Hair Qualities ^[2,3,18]
Abnormal Qualities	Hair Shaft Characteristics	Associated Syndromes
Monilethrix Beaded appearance	Normal at birth Within 1 week, hair is dull and brittle Breaks spontaneously; stubble-like appearance
Pili torti 3 to 4 twists of hair shaft on its own axis	Dry and brittle Breaks at different lengths Stands out from scalp	Menkes (X-linked) Bazex Crandall
Trichothiodystrophy Brittle hair	Fragile, dull, short Disordered hair, scalp, eyebrows and eyelashes Sulfur and cysteine deficient Copper-zinc ratio increased	Sabinas brittle hair syndrome Pollitt syndrome Amish hair-brain syndrome
Wooly hair Tight, curly	Abnormal from birth Differs from other areas of scalp Differs from family members Associated with ocular abnormalities	Epidermolytic palmoplantar keratoderma Wooly hair syndrome Wooly hair nevus: other epidermal nevi apparent
Spun glass hair Uncombable hair	Light silvery hair (lighter than expected); No pigment Inflexible hair; dry; easily breaks Glistening Teeth may have enamel defect	Uncombable hair syndrome
Trichorrhexis invaginata Bamboo hair	Present at birth; can have red, scaly skin Sparse; if present: short, dull, and breaks easily Soft abnormal hair wraps around firmer distal shaft	Netherton syndrome

Comments

Commenting is limited to medical professionals. To comment please Log-in.

Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.

processing....

Scalp Hair Characteristics in the Newborn Infant

Hair Growth and Loss

Tables

Tables

Tables

Tables

References

Authors and Disclosures

Authors and Disclosures

Sidebar

Sidebar: Internet Resources for Genetics

Comments

Email This

Feedback