Aegean H. Chan, MD, dual board-certified dermatologist and dermatopathologist, practicing in Santa Barbara and Solvang, Calif., notes that pigmented contact cheilitis is underrepresented in medical literature, with only a handful of published case reports. This makes its true prevalence unclear, but it is likely more common than reported.
She adds that delayed diagnosis is common in allergic contact dermatitis of all kinds because the skin inflammation often presents as a nonspecific rash that can be mistaken for other conditions, such as eczema. “It often takes a few visits before a dermatologist or allergist considers that the patient might be experiencing repeated exposure to an allergen,” says Chan.
The gold standard for diagnosing pigmented contact cheilitis is patch testing. This involves applying patches containing specific allergens usually on the back for a couple of days, then reading the results after removal. If a patch site develops a red, raised, or scaly reaction, that’s considered a positive result and confirms an allergic response to that substance.
“When the lips develop dark patches as a result of this allergic inflammation, that’s when we classify it as pigmented contact cheilitis,” says Chan.
