Alopecia areata is a problem where by patches of baldness can occur very quickly. Follicles still exist within the patches.
Psoriasis is a scaly problem whereby circular patches of white scale on a reddish base are formed. Variations of both these problems occur.
The cause of alopecia areata and psoriasis are very similar, both are autoimmune problems, which means that one group of white blood cells attacks some cells in the skin or hair.
People who expererience alopecia areata or psoriasis have a genetic predisposition for the problem. However, it still takes something to trigger the problem. The trigger could be a viral or bacterial infection, a vaccination, stress, trauma to the skin or exposure to a substance not previously encountered.
Stress can influence both problems through its effects on the sympathetic nervous system. Stress cause sympathetic nerves to increase there productions of noradrenalin in the skin, which increase the autoimmune reaction.
It must be emphasised that there is no treatment for either problem that works 100% of the time, a treatment that helps one person may not help another.
Genetic thinning in women shows as a thinning of hair in the top/ front area of the scalp.
Hormonally, DHT (dihydrotestosterone) is the androgen (male sex hormone) that influence genetic hair loss and the loss is oftentriggered by a change in sex hormonal levels,such as those changes associated with menopause or with the taking or stopping of oral contraceptive.
Blood tests can be run to establish whether hormonally inbalance.
Genetic thinning in men is characterised by recession at the front and / or thinning of hair around the crown area. It can be inherited from the father or mother and requires the normal levels of male sex hormones.
In the scalp, testosterone is converted to dihydrotestosterone (DHT) and it is the DHT that influence the hair follicles in the areas in questions. White blood cells are also in abundance and can lead to redness / swelling on the skin around the hair follicles.