Postinflammatory Pigment Alteration in Skin of Color

The term “postinflammatory pigmentary alteration” refers to two distinct entities: postinflammatory hyperpigmentation and postinflammatory hypopigmentation. These pigmentary changes follow may inflammation, such as from a prior rash, or trauma to the skin. In lighter skin colors, these pigmentary alterations tend to be more subtle and shorter-lived. In darker skin colors, changes in skin pigmentation are more frequent, more noticeable, and tend to persist. The appearance can deeply affect a patient’s self-confidence and result in personal distress. Furthermore, the prevalence of postinflammatory pigment changes can result in over-assumption of this diagnosis and anchoring, premature closure, or other bias—preventing additional findings or diagnoses to be sought. This can result in diagnostic error and misdiagnosis.

How does this diagnosis impact people of color?

Alterations of pigment are more obvious and notable on skin of color. There can be significant cosmetic and psychosocial distress, especially if the lesions are visible on exposed skin surfaces, such as the face or hands. When severe, postinflammatory hypopigmentation can mimic vitiligo—a diagnosis that is stigmatizing in some communities. Furthermore, some may construe pigmentary changes as infectious.

Why is it overrepresented, hard to spot, or misdiagnosed?

Postinflammatory pigmentary alteration is more often diagnosed in skin of color due to the readily visible contrast in darker skin colors and the ability of darker skin colors to form darker pigment. It may be more difficult to discern in lighter skin colors.

Postinflammatory pigmentary alteration can be overassumed as a diagnosis due to its prevalence. Clinicians may use it as a primary diagnosis and overlook the inciting condition. Alternatively, it may be erroneously diagnosed in lieu of other active skin diseases characterized by dyspigmentation, such as ashy dermatoses, parapsoriasis, or hypopigmented mycosis fungoides. The diagnosis of post inflammatory pigmentary alteration is secondary and is not exclusive of other diagnoses. There may be an active, ongoing condition. The differential diagnosis should be considered to ensure there is not active inflammation or underlying causes resulting in pigmentation changes.

Diagnosis overview

Postinflammatory hypopigmentation is the localized partial or total loss (depigmentation) of skin pigmentation that occurs after resolution of cutaneous inflammation or after skin trauma.

Postinflammatory hyperpigmentation (PIH) is similarly induced as a consequence of skin inflammation or trauma but results in darkening or hyperpigmentation of the skin.

These pigmentation changes can occur in all ages, skin colors, and sexes, but they affect patients with darker skin colors with greater frequency and severity.

The inflammatory process of these pigmentary alterations may be incited by skin conditions that induce inflammation, such as rash (eg, eczema, drug reaction), acne, bug bites, skin infection, or skin trauma (eg, procedural, mechanical, or thermal skin injury).

Although clinically benign, these pigmentary alterations can cause significant cosmetic and psychosocial distress.

Inflammation can result in an over- or underproduction of melanin in the epidermis through the effect of inflammatory mediators.

Time to resolution of these pigmentary changes is dependent on the underlying cause and severity of inflammation; it ranges from weeks to years. This is a separate diagnosis from scars, which result in persistent microstructural changes of the skin after trauma or inflammation.

What to Look For:

Asymptomatic hypopigmented, depigmented, or hyperpigmented macules or patches in the same distribution and configuration as the primary inflammatory lesions.

Diagnostic Pearls:

A history of preceding inflammatory changes to the skin helps guide this diagnosis.

Appreciation of the configuration and distribution of the pigmentary changes can help ascertain the inciting diagnosis.

Differential:

A nonexhaustive differential for postinflammatory hypopigmentation includes:

A nonexhaustive differential for postinflammatory hyperpigmentation includes:

The ProjectIMPACT blog series was created to highlight dermatologic conditions that affect people of color.

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