1. 1 TB Fitzpatrick, AZ Eisen, K Wolff, and et al , eds. Dermatology in General Medicine . 4th edn . New York. NY. McGraw-Hill., 1993 : 2710, 2715 .
2. 2 HL Arnold, RB Odom, WD James, and J Andrews . Diseases of the Skin . 8th edn . Philadelphia. W.B. Saunders., 1990 : 409, 418 .
3. 3 TP Habif . Clinical Dermatology: a Guide to Diagnosis and Therapy . 2nd edn . St Louis, MO. CV Mosby., 1990 : 225, 227 .
4. 4 RH Champion, JL Burton, and FJG Ebling . Textbook of Dermatology . 5th edn . London. Blackwell Scientific Publications., 1992 : 1093, 1098 .
5. Secondary syphilis: a clinico-pathological review