Alopecia areata is characterized by complete loss of hair in sharply defined areas of the scalp. The affected skin is shiny and slightly thin and hair pores are visible.
The following are the characteristics:
- Autoimmune disorder (where the body’s immune system starts to reject the hair for unknown reasons)
- Association with autoimmune disorders like Hashimoto’s thyroiditis, Addison’s disease, leucoderma
- Sudden physical or emotional stress may lead to hair loss in a sensitive individual (trophoneurosis)
- It is not infectious.
- Usually seen in children and young adults but may occur in any age group
- Commonly affects the scalp but may involve other hair bearing areas.
- More common in males.
- Alopecia totalis: In 5% of cases alopecia areata may become widespread and lead to total loss of hair on scalp
- Alopecia universalis: In 1% of cases the hair from the eyebrows, eyelashes, beard and all other hairy portions of the body may fall
Traction alopecia is a characteristic pattern of hair loss commonly seen in Rajasthani females, Sikh males or people who tie their hair in traditional knots and apply excessive traction in the process.
Congenital alopecia is very rare. In such cases hair may not be present at birth and will not grow at all later. It may be accompanied by other congenital defects of skin, nails, teeth etc.
- Commonly seen in young adults.
- Presence of constant dandruff like scaling from the scalp is a characteristic feature
Idiopathic Premature alopecia (masculine alopecia)
- Commonly seen in young adult males.
- Usually begins between 20-40 years of age.
- Cause is unknown but in most cases a familial predisposition is seen.
- A male hormone (androgen) is believed to be responsible for this type of alopecia.
Androgenic Alopecia in women (female pattern alopecia) is a hair loss occurring in females. Hormonal imbalance (changes in levels of androgen or estrogen) for example, in menopause many women find that the hair on the head is thinned, while facial hair is coarser. Genetic factors may also play a role.
Senile alopecia is characterised by symmetrical thinning and loss of hair.
- Common after 45-50 years of age.
- It is a degenerative process (occurring as a result of old age), therefore, no treatment is satisfactory.
Primary cicatrical alopecia
- It is a type of alopecia associated with scarring.
- Mainly affects young adults.
- Common in males as compared to females.
- Cause is unknown.
- Shedding of large quantity of normal hair in certain stressful conditions like pregnancy, surgery, acute psychiatric illness and physical or emotional trauma
- Hair loss stops spontaneously over a few month