Lip licker's dermatitis
Lip licker's dermatitis, also called  irritant contact cheilitis, is a type of skin inflammation around the lips due to saliva from repetitive lip licking. The resulting scaling, redness, chapping and crusting make a well-defined ring around the lips. The rash may extend as far as the tongue can reach and frequently spares the angle of the mouth.

It is treated with simple moisturisers, emollients, and sometimes topical steroids. It is different to perioral dermatitis, which spares the vermillion border and is worsened by topical steroids. Children are affected more often than adults.

Signs and symptoms 

Redness around the lips in circumoral distribution with dryness and scale is typical. Chapping may also occur, especially in cold weather.

Causes 
Repeated licking resulting in a cycle of wetting and drying causes the redness, fissuring, and scale. It can also occur with lip chewing, thumb sucking, or excessive drooling.

Wind instrument players may also experience lip licker's dermatitis.

Compulsive licking of lips causing lick lip dermatitis is also seen as psychological disorder.

Persistent and continuous breathing from the mouth can cause dry lips and result in the temptation to repeatedly lick the lips with the aim to keep them moist.

Diagnosis 
The diagnosis of lip licker's dermatitis is from the history and inspection of the rash. It is important to distinguish it from allergic contact dermatitis and perioral dermatitis which are characterised by papules in the perioral area and sparing of the vermillion border, and worsened by topical steroids.

Treatment 
Generous application of bland emollients can improve the rash. However, complete resolution will not occur until the lip licking stops. Breaking the cycle of dryness then licking followed by more dryness is key to treatment. Sometimes, unlike in perioral dermatitis, topical steroids may be used for few days only.