Alopecia areata can strike anyone, and it can appear as early as childhood for both men and women. It’s characterized by patchy, sudden hair loss on your scalp, face, and possibly other areas of your body.
Diagnosis: Positive result determined based on any of below conditions. 1. Hair loss lasts over 6 months. 2. Hair loss areas enlarging or increasing. 3. Hairs become loosen. The pull test is positive. 4. There’re broken hair or “!”symbol hair in hair follicle.
Diffuse alopecia: it affects the scalp in a general distribution. This is in contrast to localised or focal alopecia, which is characterised by patchy hair loss.
Ophiasis alopecia areata: it causes hair loss in a band shape around the sides and back of your head. Occurs from hairline and spreads to centre. Usually, hair loss together with hair growth. Or hair grows very slowly. Even no new hairs grow for quite a while.
Pseudo alopecia areata is also known as Pseudopelade of Brocq (PBB) or Brocq Pseudopelade: The patches of hair loss present in PBB may be single or multiple. They are usually small, discrete, round or oval, and asymmetrical. The underlying skin is typically smooth, soft, and flesh-colored or white, with little, if any, inflammation.
Tinea capitis, also called scalp ringworm, is a fungal infection of the scalp that’s a common cause of hair loss in children. This condition causes hair to fall out in patches, sometimes circular, leading to bald spots that may get bigger over time.
Black dot ringworm of the scalp: Often occurs in children. Hairs don’t fall completely. Most hairs are broken. Left hair roots accompany with scale. And fungi could be detected easily.
Alopecia syphilitica (AS) is an uncommon manifestation of secondary syphilis, with a prevalence that ranges from 3% to 7%. It is a nonscarring alopecia that can present in a diffuse pattern, a moth-eaten pattern, or a mixed subtype.
Localized scleroderma, called “linear” or “morphea”, is an autoimmune condition that causes hardening and inflammation of the skin and muscles in one part of the body.
Scarring alopecia, also called cicatricial alopecia, is a type of hair loss caused by the destruction of hair follicles. It’s usually the result of infections, chemicals, burns or autoimmune disorders. Hair loss due to scarring alopecia can be permanent because hair can’t grow back without healthy hair follicles.
Trichotillomania ,
Trichotillomania, also known as trich, is when someone cannot resist the urge to pull out their hair.They may pull out the hair on their head or in other places, such as their eyebrows or eyelashes. Trich is more common in teenagers and young adults.
Trichotillomania (TTM), also known as hair pulling disorder or compulsive hair pulling, is a mental disorder characterized by a long-term urge that results in the pulling out of one’s hair.This occurs to such a degree that hair loss can be seen. A brief positive feeling may occur as hair is removed Efforts to stop pulling hair typically fail. Hair removal may occur anywhere; however, the head and around the eyes are most common. The hair pulling is to such a degree that it results in distress.
The disorder may run in families. It occurs more commonly in those with obsessive compulsive disorder. Episodes of pulling may be triggered by anxiety. People usually acknowledge that they pull their hair. On examination broken hairs may be seen. Other conditions that may present similarly include body dysmorphic disorder, however in that condition people remove hair to try to improve what they see as a problem in how they look.
There’s about 4~16% alopecia areata associated with Vitiligo.
Causes:
Psychoneurotic causes：Nerve stimulation, mental trauma, severe anxiety and tension, poor sleep, excessive fatigue, etc.
Autoimmune causes: Autoimmune diseases such as type 1 diabetes, rheumatoid arthritis, thyroid disease, vitiligo, etc.
Genetic factors, family history, Hereditary allergic constitution.
Other causes, endocrine disorders, intestinal parasites, local lesions, trauma, infection, poisoning or other visceral diseases
Characteristic of alopecia areata:
This condition can affect adults and children, and hair loss can begin suddenly and without warning. Hair from the scalp typically falls out in small patches and is not painful. Hair in other parts of the body, including the eyebrows and eyelashes, may also fall out. Over time, this disease may lead to alopecia totalis, or complete hair loss.