Book Review Dermatology Edited by Milton Orkin, Howard I. Maibach, and Mark V. Dahl. 696 pp., illustrated. Norwalk, Conn., Appleton and Lange, 1991. $37.95. Immunologic Diseases of the Skin Edited by Robert E. Jordon. 646 pp., illustrated. Norwalk, Conn., Appleton and Lange, 1991. $125.