If there are patches on the head or the body which are completely devoid of hair, it could be Ophiasis, a type of Alopecia Areata. Ophiasis is Greek for "snake" as it is recognized by a serpent like design on the temporal or occipital area of the scalp.
The bald patch will be very smooth and may increase in size. It leaves no scar and is inflammatory. It could affect anyone, young and old, man or woman. It is not a dangerous disease but it affects the psychology of the patient as it may lead to total loss of hair and may make the patient a recluse in society.
There are three steps in the growth of follicles of hair. Anagen implications activity in the hair follicle. Hair grows in this stage. Catagen implies growth retardation. Telogen is the time for the follicle to rest. Hair falls at this stage. The cycle is complete and anagen starts again.
In the anagen stage follicles may get inflamed. This is Ophiasis. They enter the telogen phase instead of catagen. If this keeps happening weak strands of hair are produced from the follicles.
Some researchers believe that the follicles quickly proceed from the first stage to the last one. Some believe that the follicles get captured in the last stage. In the early stages of the disease the cycle gets disrupted. This leads to a large number of hair follicles in each stage.
Clumps of hair of the last stage fall from all parts of the body. If the roots are visible they are telogen follicles. At the borders of the bald patch are broken hair which look like exclamation marks.
This is how Ophiasis occurs.