DDx based on skin site affected
- Lower more than upper vermilion lip
- Background of photodamage
- History of actinic keratoses, basal cell carcinoma, squamous cell carcinoma
- May have diffuse hyperkeratosis and/or discrete actinic keratoses
- Lower & upper lip involved
- Often extends onto cutaneous lip
- Most common cause: lip licking
- Atopic diathesis
- Lesions of atopic dermatitis in other areas
- Angular fissure
- Xerosis
- Upper and lower lip involved
- Allergens include: fragrances/flavorings, preservatives, sunscreens, topical antibiotics (e.g. neomycin), metals (e.g. nickel), topical corticosteroids, propolis
- Predisposing factors: dentures/orthodontic appliances, inhaled/oral corticosteroids, diabetes mellitus, HIV infection, deep oral commissure grooves, drooling
- Erosions are possible
- Angular fissures
- Increased likelihood of having oral thrush
- Oral ulcerations
- Lacy pattern on lips and buccal mucosa
- Lesions of lichen planus or graft versus host disease elsewhere
- Diffuse swelling of lip
- Secondary changes may develop
- May be associated with scrotal tongue, 7th nerve palsy, Crohn disease