Skin diseases are a bit like the common cold. Apart from some of the skin cancers, they may vary enormously from mild condition which may affect only the appearance of skin to severe disease which are totally incapacitating. Conditions such as warts and acne are almost universal at certain ages. However whether people recognize or report many of these common conditions as disease will vary according to the area affected and the severity of the problem.1 An early diagnosis and identification of these conditions that are mostly curable by treatment is important as this not only helps in treating the patients but also helps in preventing the spread of communicable diseases. Skin diseases and their complications are a significant burden on the nations. There are probably at least 2000 different skin conditions that might present to the dermatologists. Distribution of skin diseases differ from country to country and even city to city. Some factors like genetic, environment, race, occupation, nutrition and habits can influence the pattern of skin diseases. A cross section study of pattern of skin diseases among the local population in rural Allahabad was conducted in October 2005. Of them 7.86% persons presented with skin diseases, among these 62.2% were males and 37.8% were females. The majority of the population was in the age group of 11–20 years with 31.4%, followed by 21–30 year group with 19.3%, 31–40 year group with 14.6%, < 10 year group with 12.8%, 41–50 year group with 11.3%, 51–60 year group with 7.5% and > 60 year age group with 3.1%.2 According to WHO total 18 prevalence studies conducted in year 2005 of the general population in developing countries (sub-Saharan Africa). All reported high prevalence figures for skin diseases (21-87%), the following disorders being the commonest in children: taqayyahul jild (pyoderma) (0.2-35%) sa'fa (tinea capitis)  (1-19.7%),  jarb (scabies) (0.2-24%), viral skin disorders (0.4-9%), qummarur ras (pediculosis capitis) (0-57%), iltehabe jild (dermatitis) (0-5%),and reactions due to insect bites (0-7.2%).3

Dermatology, the science of skin and its appendages is one of the many specialties that evolved from general internal medicine during the course of 19th century. Till this time physicians with few exceptions were little concerned with the skin apart from the exanthematic eruptions of acute fevers.4,5 Clinically, the diagnosis of any particular skin condition is made by gathering pertinent information regarding the presenting skin lesion, including the location, symptoms, duration, arrangement, morphology and colour. However the physicians of Unani system of medicine were well versed with skin diseases and they have given an ample description of different dermatoses in their treatise since antiquity. Ali Bin Raban Tabri, an eminent Arab physician narrated sa'fa (tinea capitis), juzam (leprosy) systematically in his treatise Firdausul Hikmat.6 Ali Ibn Abbas Majoosihas stated that some of the skin diseases have internal causes and others have external causes. Few of these diseases are generalized on external surface of body such as judri (small pox), juzam,bahaq(Pityriasis versicolor), and bars (vitiligo). Whereas some appears on the specific parts such as busoore labnia (acne vulgaris) and safa. Juzam leads to yaboosat in all the organs of the body which causes destruction of different organs of the body. Jarb (scabies) are caused due to mixing of balgham shor mirari in blood. Body wants to get rid of these matters and thus it is collected under the skin which causes itching. The cause of bars is buroodate dam, ghalba khilte balgham.7Abul Hasan Ahmad bin Mohd Tabri had classified judri into 4 types according to their appearance over the body. With difference in sign and symptoms, bars are classified to different types. These are shiny and smooth spots over the different parts of body. The causes of shar'a (urticaria) as given by Tabri are due to heat in blood or khilte saudawia. These appears as reddish brown maculae over the skin and clear fluids oozes out but sometimes these are dry.8

Ajmal khan has described in his treatise Haziq, jarb of two types; dry and wet, with their causes khilte sauda and rutoobate balghamia respectively. In case of shar'a; small reddish maculae appears all over the body, which are caused due to disturbance in digestive process or heavy meal or excessive fatty diet. The incidence is more in females and elderly. He also stated about busoore labnia, juzam and bars in detail with their treatment in his treatise Haziq.9  Ibn Zuhar in his treatise  Kitabut Taiseer stated various skin diseases in detail and also provided their effective treatments.10

In short every eminent physicians of Unani system of medicine had given their views and specific treatments for the different skin ailments.