Lichen planus pigmentosus, ashy dermatosis, erythema dyschromicum perstans, or acquired spontaneous macular hyperpigmentation?

Introduction: Clinical and histopathological features of acquired spontaneous macular hyperpigmentation appear to overlap in the conditions described as lichen planus pigmentosus, ashy dermatosis, lichen pigmentosus, and erythema dyschromicum perstans.

Methods: Ten consecutive patients with acquired hyperpigmented macules over 5 mm in size without a history of inflammation were studied. Salient points in the history and examination were recorded and biopsies were assessed in all the patients.

Results: Age ranged from 4–60 years. Seven were females. None had a history of lichen planus or erythematous lesions prior to pigmentation. There was no history of contact dermatitis. Face was the commonest site involved, but lesions were seen in non-exposed areas as well. Lesions were non-itching, ashy gray macules with ill-defined margins, sometimes becoming confluent. Size of lesions varied within and between patients. Pigmentary incontinence, epidermal thinning, and mild hyperkeratosis were consistent features in all 10 biopsies. Paucity of inflammation was a notable feature in all cases. Focal basal cell degeneration was seen in 3 biopsies.

Conclusion: Acquired spontaneous macular hyperpigmentation should not be linked to lichen planus when not associated with same. A consensus opinion on terminology is needed to avoid confusion as different workers seem to label the same condition by different names.