Focal or patchy hair loss Alopecia Areata has been know for a long time and is commonly manifested by patchy areas of complete hair loss on the scalp and other body parts, also in severe cases it can progress to complete loss of all body hair. Although Hippocrates first used the term Alopecia (literally translated as "fox’s disease"), the characteristics of the hair loss disease we now know to be Alopecia Areata were first described by Cornelius Celsus in 30 A.D. Celsus described two forms of alopecia. The first he described as complete baldness occurring in people of all ages. The second he called "ophiasis", which literally translates from Latin as "snake", due to the winding pattern the bald region spread across the skin. He suggested ophiasis was only seen in children. Alopecia Areata is sometimes known as "Area Celsi" in tribute to Cornelius Celsus. Alopecia Areata has been given many different names throughout history, however, the actual term "Alopecia Areata" was first used by Sauvages in his "Nosologica Medica", published in 1760 in Lyons, France. Alopecia Areata is a non-scarring, inflammatory, hair loss disease that is seen in men, women and children. This condition is commonly manifested by patchy areas of complete hair loss on the scalp and other body parts. In severe cases, Alopecia Areata can progress to complete loss of all body hair. While not a life threatening condition, Alopecia Areata nonetheless has serious implications for the victim and family members because of its psychological and sociological backlash.  The exact etiology of this disease is still has be established, however, there is a lot of evidence to support the fact that Alopecia Areata is a multi-entity disorder with causes that are multifactorial, including evident autoimmune and genetic components. The disease presents with the loss of scalp and body hair by interruption of their synthesis. There is no destruction or atrophy of the follicles, and therefore the hair loss can be reversible. Normally, hair growth in each hair follicle occurs in a cycle. There are four main phases of the hair growth cycle Anagen (active growth phase), Catagen (period of controlled regression) and Telogen (resting state) and Exogen (while actually shedding out the hair fiber). Alopecia Areata primarily affects the hair follicle as it enters the Anagen phase, and studies further indicate that the initial event in the development of Alopecia Areata is the premature precipitation of Anagen follicles into the Telogen state of the hair follicle cycle. So in early active Alopecia Areata, the hair cycle is disrupted and there is an abnormal shift in the expected ratio of Anagen, Catagen and Telogen hair follicles. Hairs that fall out appear to have "roots" and are observed to be Telogen hairs when examined under the microscope. There is currently no conclusive diagnostic test for Alopecia Areata, so trichologists basically deduce Alopecia Areata by a process of elimination of other hair loss causes and close examination of the lesion itself. Typically, the initial Alopecia Areata lesion appears as a smooth bald patch sometimes within 24 hours. Some people feel a tingling sensation or pain in the affected area. The scalp is the most commonly affected area but Alopecia Areata can present in any region of hair on the body. Hair pull tests are sometimes conducted at the margins of lesions. If hair is easily pulled out, it is indicative that the lesion is active and further hair loss should be anticipated. The hair fiber that falls out in Alopecia Areata has been the subject of several analytical studies and is sometimes used to diagnose Alopecia Areata. Using scanning electron microscopy the hair fibers falling out from the edge of an expanding bald patch can look very unusual. Frequently, the part of the hair fiber furthest away from the scalp (the oldest part of the hair) looks normal. Closer to the scalp (newer part of the hair) and it can look quite aberrant, as the shape of the fiber becomes increasingly irregular the closer to the scalp we look. This involves deposits of unordered keratin and constrictions in the hair fiber. The cuticle can be missing and there can be longitudinal cracks along the length of the hair. Analysis of the hair fiber shows the constituent keratins to remain the same but the way they are assembled to make up the fiber becomes increasingly abnormal. The irregular construction of the hair gives it weak spots where it can readily break off. Short, 1 to 2-mm fractured hairs can frequently be seen at the active margins of alopecia areata. These hairs are commonly described by the clinician as exclamation-mark hairs because these characteristic hairs fracture at their distal end and taper proximally to a pencil point, giving them the appearance of an exclamation mark. Some trichologists use presence of exclamation mark hairs as diagnostic for Alopecia Areata, however, it has been shown that exclamation mark hairs can occasionally occur in other conditions as well. Hairs that are less severely damaged may continue in anagen but produce dystrophic hairs as described earlier. Alopecia Areata commonly affects pigmented hairs and is less able to attack un-pigmented or white hairs. Alopecia Areata runs an unpredictable course and may last many years with some re-growth, or it may cycle through expression and remission. In some cases, it may only last for a short period and normal hair growth can be quickly reestablished within months. Because of partial Telogen-to-Anagen conversion, the initial regrowth in Alopecia Areata may consist of short, white, "fuzzy" hairs. Some people with Alopecia Areata may experience changes in hair color during, or after, an episode of hair loss and at times these color changes can be permanent. The phenomena that pigmented hairs are more frequently affected by Alopecia Areata and that regrowing hair is often initially white are still not explained scientifically.