The approach uses the sequence of sign onset alongside household demographic characteristics to infer serial intervals, community hazards of disease, and person-to-person hazards of transmitting and to investigate how the hazard of transmission may be affected by the following covariates: the age group of the case patient, the age group of family members contact, home size, and symptoms in the event affected person . The assumption is that there is certainly a period lag of at least one day between the onset of symptoms in a patient and the starting point of symptoms in the people they infect. The results of a thorough sensitivity analysis investigating the robustness of the outcomes with respect to modeling assumptions are shown in the Supplementary Appendix. The parameters of the transmission model were estimated by using Bayesian Markov chain Monte Carlo sampling.The Greek and Roman cultures utilized a mixture of substances such as natural oils and resins with pumices to even and exfoliate the skin. Across Asia, in India, they replaced the natural resins with urine to achieve the same results and rather drastically the ancient Turks attained their exfoliation by in fact singeing the skin. The Birth of Modern Dermatology The term dermatology itself Comes from the Greek for ‘skin’ derma and ‘to learn’ logy via first the French dermologie and subsequently the latinised term dermatologia. What we have now consider as dermatology though could be traced back again to the early 16th century in Europe and much of this early work centered on the use of chemical substances from classical practices as well as sunlight on circumstances such as eczema and psoriasis.