Casal collar

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A boy with casal collar caused by pellagra.

The Casal collar or Casal necklace is a

medical sign in which there is a redness and darkening of the skin around the neck, seen in people with pellagra.[1] It becomes prominent following exposure to sun, and can be itchy with a burning feeling and pain.[2] It can blister and weep, and turn into thick dark skin, with a coppery hue.[2] If prolonged, the skin becomes thin, dry and smooth.[2]

It is caused by a lack of the vitamin

Seborrheic dermatitis may appear similar.[2]

The sign is named after Gaspar Casal.[3]

References