A<unk> , also known as a<unk><unk><unk>  line or an infraorbital<unk> , is a<unk>  or line in the skin below the lower eyelid. It can simply be an ethnic/genetic trait, but was found in one study to occur in 25% of patients with atopic dermatitis. The presence of<unk> s can be used as a diagnostic marker for allergy with a sensitivity of 78% and specificity of 76% according to one study. Such<unk> s are also common among certain ethnic groups such as Africans, Tatars, Slavs, Balts and Finnic peoples, and are not known to be associated with any medical condition in these. The pathophysiology of this sign is not clear. One proposed mechanism is that continuous spasm of the superior tarsal muscle and skin edema could be due to hypoxia from poor circulation. A<unk>  should not be confused with an "allergic shiner", which is a purple-gray discoloration with associated fullness beneath the lower eyelid. This is related to the accumulation of blood and other fluid in the infraorbital groove resulting from nasal congestion.
Dennie–Morgan fold
Curschmann's spirals
Munk's Roll
Mees' lines
Tycoon's cap
Gräfenberg's ring
Pastia's lines
Woronoff's ring