[1] Palo Alto Fdn Med Grp, Dept Dermatol, Mountain View, CA 94040 USA
[2] Univ So Calif, Keck Sch Med, Los Angeles, CA 90033 USA
[3] Kaiser Permanente Los Angeles Med Ctr, Dept Dermatol, Los Angeles, CA USA
[4] Univ Calif San Francisco, San Francisco, CA 94143 USA