Stubborn ring of rash around a boy's mouth

THE CASE

The mother of a healthy 11-year-old boy brings him to the office for help to clear a rash that has persisted around his mouth for 3 months. Although the boy rarely licks his lips, he does not use lip products and has not changed his dental products. 

Diagnosis: Lip-licking dermatitis

Etiology and epidemiology

Lip-licking dermatitis is a form of chronic irritant contact dermatitis caused by repeated exposure of the lips and perioral area to saliva.^1,2 This condition is commonly found in young children, but it can also be seen in adolescents and adults, and it is typically worse in the winter months.²

The dermatitis results from repetitive cycles of maceration and drying from repeated licking of the lips, which damages the epidermal barrier causing irritation and inflammation.³ Stratum corneum is the outermost semi-impenetrable layer of the skin that retains moisture and constitutes the major physical barrier of the skin. Cells in this layer, corneocytes, bind water with the aid of surface lipids and envelope proteins.⁴

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Frequent wet-dry episodes erode surface lipids causing disruption to the corneocytes and lead to the loss of skin water content and the release of inflammatory cytokines, including tumor necrosis factor alpha and interleukin-1.^1,3 This translates to the classic ring of dry and inflamed skin observed on clinical presentation.

Clinical findings

Well-demarcated and symmetric erythema of the upper and lower cutaneous lip with the involvement of the vermillion border is characteristic of lip-licking dermatitis. The inside of the mouth and areas beyond reach of the tongue are spared. It can present with overlying red papules, scaling, crusting, or fissures. In skin of color, a hyperpigmented or hypopigmented ring is more typical than erythema. Symptoms may include dryness and burning, and, in contrast to allergic contact dermatitis, itching is typically modest or absent.^1-3

NEXT: Differential diagnosis and management

Differential diagnosis

Lip-licking dermatitis may be confused with periorificial dermatitis, allergic contact dermatitis, atopic dermatitis, seborrheic dermatitis, and candidiasis (angular cheilitis or perlèche).^1-3

·      Periorificial dermatitis may develop around the eyes, nose, and mouth in children and young adults and probably represents a variant of rosacea. It also has been associated with the use of topical and inhaled steroids. However, unlike lip-licking dermatitis, it spares a narrow zone immediately adjacent to the vermilion.

·      Allergic contact dermatitis can present similarly to irritant contact dermatitis, but history would reveal exposure to triggering substances such as lipsticks, dental products or devices, musical instruments, food, or medication. Atopic dermatitis would typically affect other areas of the body and favor flexural or extensor surfaces depending on the patient’s age.

·      Seborrheic dermatitis presents with erythema with overlying yellow greasy scale that favors the scalp, eyebrows, and nasolabial folds. Perioral distribution is not typical for seborrheic dermatitis.

·      Perlèche can present similarly but oral involvement typically occurs in patients with underlying illness or who are immunosuppressed. It would normally respond to topical antifungal therapy.

Lip-licking dermatitis is a clinical diagnosis based on history and physical examination. Often parents or the physician observe repeated lip-licking behavior that can lend support to the diagnosis.

Management

The main goal of therapy is to break the frequent wet-dry cycle, restore water and lipid content to the skin surface, reduce inflammation, and prevent further transepidermal water loss.¹ Generous and frequent application of emollients, such as petroleum jelly, provides a barrier that can help retain moisture and enhance the efficacy of topical medication.⁵

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A short course of low- to mid-potency topical steroids or topical immunomodulators (tacrolimus ointment or pimecrolimus cream) may expedite resolution in more recalcitrant conditions.^1-3 However, topical steroids must be monitored to avoid chronic use, which may result in the development of periorificial dermatitis. Patient and parents should know that complete resolution and absence of recurrence necessitate eliminating the inciting factor, which in this case is repeated licking of the lips. Behavioral therapy may be necessary, and it can be very effective in modifying the habitual practice.^6,7

Patient outcome

The patient and his mother were educated on the etiology of this condition. The boy was counseled that minimizing or stopping his habitual lip-licking could greatly improve the dermatitis. He was also advised to start twice-daily application of topical tacrolimus 0.1% ointment in conjunction with frequent use of emollient at least 5 to 10 times a day. A follow-up visit 4 months later showed dramatic improvement, and he was advised to continue frequent emollient application.

REFERENCES

1.    Weston WL. Contact dermatitis in children. UpToDate. Available at: https://www.uptodate.com/contents/contact-dermatitis-in-children. Updated March 7, 2017. Accessed September 7, 2017.

2.    Fox A, Dasher D, Bernhard JD, et al. Lip-licking dermatitis. VisualDx. Available at: https://www.visualdx.com/visualdx/diagnosis/lip-licking%20dermatitis?diagnosisId=53407&moduleId=10. Updated February 12, 2015. Accessed September 7, 2017.

3.    Watt CJ, Hong HC. Dermacase. Lip licker's dermatitis. Can Fam Physician. 2002;48:1051, 1059.

4.    Marks JG Jr, Miller JJ. Structure and function of the skin. In: Lookingbill and Marks’ Principles of Dermatology. 5th ed. Elsevier Saunders; 2013:2-10.

5.    Buraczewska I, Berne B, Lindberg M, Törmä H, Lodén M. Changes in skin barrier function following long-term treatment with moisturizers, a randomized controlled trial. Br J Dermatol. 2007;156(3):492-498.

6.    Azrin NH, Nunn RG, Frantz-Renshaw SE. Habit reversal vs negative practice treatment of self-destructive oral habits (biting, chewing, or licking of the lips, cheeks, tongue, or palate). J Behav Ther Exp Psychiatry. 1982;13(1):49-54.

7.    van de Griendt JM, Verdellen CW, van Dijk MK, Verbraak MJ. Behavioural treatment of tics: habit reversal and exposure with response prevention. Neurosci Biobehav Rev. 2013;37(6):1172-1177.