[1] Hypopigmented lesions can range in color from hypopigmentation to depigmentation, and their size, form, and primary inflammatory dermatosis frequently correspond with each other.
Complete depigmentation is more noticeable in people with darker skin and is frequently observed in cases of discoid lupus erythematosus and severe atopic dermatitis.
Certain conditions, like lichen striatus (LS) and pityriasis lichenoides chronica (PLC), typically cause postinflammatory hypopigmentation as opposed to hyperpigmentation.
Postinflammatory hypopigmentation can also result after cutaneous injuries caused by burns, irritants, and dermatological operations (such as chemical peels, dermabrasion, cryotherapy, and laser therapy).
[2] Pityriasis lichenoides chronica frequently manifests as diffuse hypopigmentation with a small number of scaly papular lesions in patients with dark skin.
Different hypomelanotic conditions can be distinguished using confocal laser scanning microscopy based on patterns of distribution and melanin content.
[7] The histopathology of postinflammatory hypopigmentation reveals generic features such as the presence of melanophages in the upper dermis, varying degrees of superficial lymphohistiocytic infiltration, and decreased epidermal melanin.
[2] Postinflammatory hypopigmentation has been treated by twice-daily administration of a medium-potency topical steroid combined with a tar-based preparation, albeit the mechanisms underlying this are still poorly understood.
[2] An open-label pilot study found that topical pimecrolimus cream helped dark-skinned patients with postinflammatory hypopigmentation related to seborrheic dermatitis.