Postinflammatory hypopigmentation in Adult
Postinflammatory hypopigmentation can occur in patients of all ages, sexes, and skin types, and is more visibly pronounced in those with darker skin phototypes. It can be seen as a sequela of many inflammatory skin diseases (atopic dermatitis, seborrheic dermatitis, psoriasis, lichen striatus, pityriasis lichenoides chronica, lichen planus, sarcoidosis, discoid lupus erythematosus), infections (zoster, pityriasis versicolor, impetigo), procedures (chemical peels, laser, dermabrasion), and burns.
Time to resolution of hypopigmentation is dependent on the underlying cause and severity of inflammation, ranging from a few weeks in minimally hypopigmented lesions to several years in depigmented lesions (eg, discoid lupus erythematosus and burns).
Related topic: Drug-induced hypopigmentation
L81.9 – Disorder of pigmentation, unspecified
277787003 – Post-inflammatory hypopigmentation
Differential Diagnosis & Pitfalls
- Pityriasis alba – Scaly, oval, ill-defined macules and patches with mild hypopigmentation; more common in children.
- Pityriasis versicolor – Coppery orange under Wood's lamp; potassium hydroxide (KOH) prep of scale shows a characteristic "spaghetti and meatballs" appearance.
- Sarcoidosis – Histology will reveal dermal noncaseating granulomas.
- Progressive macular hypomelanosis – Punctiform red fluorescence under Wood's lamp.
- Leprosy – Associated with hypoesthesia.
- Mycosis fungoides – Early-stage variant involving hypopigmentation on the trunk and extremities that may be pruritic.
- Scleroderma – Circumscribed hypopigmentation with perifollicular pigment retention.
- Hypopigmented lesions in extramammary Paget disease
- Medication – Particularly high-potency topical and intralesional corticosteroids.
- Bier spots (physiologic anemic macules) – Transient, irregularly shaped, hypopigmented macules on the extremities due to physiologic vascular abnormalities; most often seen in young adults.
- Idiopathic guttate hypomelanosis (IGH) – Rare in children and young adults. Sharply demarcated, hypopigmented (and sometimes depigmented) macules on the extremities.
- Chronic arsenic exposure – Hypopigmented lesions resemble IGH but are scattered on a hyperpigmented base.
- Leukoderma syphiliticum (see secondary syphilis)
- Vitiligo – Pigment loss is total.
- Discoid lupus erythematosus – Pigment loss, often in the center of lesions with a rim of hyperpigmentation; associated with cutaneous atrophy / scarring.
- Chemical leukoderma – History of bleaching agents, phenol-containing cleaners, and glues.
- Depigmented extramammary Paget disease
- IGH – See above.
- Leukoderma punctata – Rare phototherapy-induced eruption; clinically similar to IGH but presents in younger patients and resolves with phototherapy discontinuation.