History:

 A 22-year-old felae presented with  brwonish hyperpigmentation confined to the lower half of the face and bilaterally involved the cheeks, nasolabial folds and upper lip of one month duration. Clinically, the rash doesn't fit FDE, melasma or lichen planus. No history of taking any systemic drug or local medication. Detailed history" was taken which revealed that she had a previous mild perioral pigmentation (it's cause ?) for which a relative-friend had advised her to wipe off it with a citrus fruit peel !!! Few days later a severe degree of hyperpigmentation has appeared in different areas where wiping has been done !!!