It is the outline of the lesion as observed from above. The most common configurations are:
Annular: Doughnut-shaped lesions. Fungal infections present as red rings with the scaly surface.
Linear: Lesions arranged in a line. For example, streaks of small vesicles on an erythematous base.
The most common linear lesion is the rash of poison ivy, also called rhus dermatitis (rhus is the Greek
word for sumac, which describes various shrubs or small trees). Some species of sumac, or rhus, include
poison ivy and poison oak—both cause an acute itching rash on contact.
Reticular: Lesions organized in a net-like cluster
Gyrate: Lesions with a serpiginous (or polycyclic) configuration—as in gyrate erythema
Annular: Doughnut-shaped lesions. Fungal infections present as red rings with the scaly surface.
Linear: Lesions arranged in a line. For example, streaks of small vesicles on an erythematous base.
The most common linear lesion is the rash of poison ivy, also called rhus dermatitis (rhus is the Greek
word for sumac, which describes various shrubs or small trees). Some species of sumac, or rhus, include
poison ivy and poison oak—both cause an acute itching rash on contact.
Reticular: Lesions organized in a net-like cluster
Gyrate: Lesions with a serpiginous (or polycyclic) configuration—as in gyrate erythema