Semiology scalp

The scalp is the thick skin covering the skull and containing the hair and glands.

Hair : the hair is the first thing you can inspect the scalp, and this has a color, consistency, appearance and distribution. and all these features vary by sex and age.

The hair was classified into 3 groups:

- Leicotricos or straight hair.

- Cimotricos or wavy hair.

- Ulotricos or frizzy hair.

We must also inspect the number of hairs per square centimeter .

It is also important to know this number, as it will help us meet certain conditions, the normal amount among people aged 16 to 45 years is 175-300 hairs per cm2, this amount decreases with age.

Amount of hair

- The amount of hair may be normal, abundant or scarce, with the presence of alopecia or baldness.

- In male hypogonadism he has abundant hair which is unlikely to have baldness.

- Hypothyroidism occurs in women and men with little sparse hair, being more common in women.

Hair distribution

The normal distribution of hair can be modified by endocrine and various alterations depending on gender.

In man the feminization (abundant and no tendency to baldness hair) that can cause occurs:

- hypogenitalism

- Testicular Tumor

Virilization in women and this can occur due to hormonal factors:

- Gonadal (ovarian tumor)

- Adrenocortical (Adrenogenital Syndrome)

- Pituitary (Cushing's syndrome and acromegaly)

- Thyroid disease (Basedow)

Hair color

The hair may exhibit changes in their normal coloration, this may discolor and can be congenital and acquired.

Discoloration is called congenital albinism or leucotrichia, and discoloration acquired graying of hair is called and this may be physiological or premature.

Physiological or senile graying : The hair discoloration that occurs during the second half of adulthood, between 30 and 50 years old, this loss of color begins in the temporal region of the skull and advances to other regions, hair takes this coloration as decreases the amount of nutrients to the hair matrix filling the air.

Premature graying : This discoloration occurs in young and can be genetic or family cause. But there are different causes such as:

- Hyperthyroidism: thin, sparse and graying on the forehead, or the temporal region of one or both sides hair.

- Eunuchism

- Lack of vitamin A: loss of hair shine and dryness.

- Essential hypochromic iron deficiency or anemia: There dryness of hair

- Violent emotional shocks: this is an unusual event, which not been fully demonstrated.

Appearance and consistency of hair

The hair undergoes various changes in many diseases such as:

- Hyperthyroidism: thin and sparse hair.

- Myxedema: dry and brittle coarse.

- Cretinism: short, dry, dark and bristly.

- Mongolism: thin and smooth.

- Hypoparathyroidism: rough, dry and brittle.

- Achylic Cloroanemia: brittle and fall.

State scalp

- Seborrea: the excessive production of sebum, start at the top of the head and asia expands the occipital and temporal region.

- Darto wheel or dandruff: epidermal peeling skin of the head.

- Pediculosis capitis: is the presence of parasites, scratching or nits pyoderma lesions. This condition exposes poor hygiene.

- Subcutaneous lipomas: be single or multiple variable, soft and normal adipose tissue formed by volume.

- Multiple skin disorders are cutaneous fungal infections and skin estafilocosicas.

Apart from all these ailments afflicting the scalp, the most important is the alopecia or baldness which can be a normal or abnormal hair and the most common deficiency are premature and senile.

Premature alopecia : occurs between 18 and 25 years, begins to thin first vertex (tonsure) and then at the temples (temporal gulfs). In the male presents the Hippocratic baldness , a baldness that respects the neck and sides for a long time. Women only exceptionally reach male pattern baldness.

This is hereditary alopecia and is related to androgens, and a seborrhoeic scalp condition.

Senile alopecia : can be caused by skin problems and has the same characteristics.

pathological alopecias

- For infection: induced secondary syphilis, it occurs as a diffuse alopecia, but incomplete with clearer nummular areas. scalp looking like "ruined skin."

- By poisoning: caused by thallium acetate, when the poisoning is severe and massive alopecia totalis occurs.

- By endocrinopatías: as in hypothyroidism, in which there is a thick, brittle hair that grows very slowly.