<unk>  is limited to the soft tissue of the periodontium, appearing as a red line 2–3 mm in width adjacent to the free<unk>  margin. Unlike conventional periodontal disease, though,<unk>  is not significantly associated with increased levels of dental plaque. The prevalence of<unk>  remains unclear and there is no known treatment.
Linear gingival erythema
Hypertrichosis simplex of the scalp
Pearly penile papules
Subconjunctival injection
Palmar erythema
Cracked nipple
Periorbital hyperpigmentation
Crenated tongue