June 06, 2022

Post Inflammatory Hyperpigmentation

There is a possibility that combinations of hormonal activity could cause hyperpigmentation.

For instance, the combination of ACTH (adrenocorticotrophic hormone) and aMSH could activate hormone receptors to trigger hyperpigmentation, hypopigmentation or post inflammatory hyperpigmentation.

Post-inflammatory hyperpigmentation (PIH) is a reactive hypermelanosis after an inflammatory skin condition. PIH can occur at any age, in any skin type and has no gender or preference; however, inflammation elicits a heightened response from hyper-reactive melanocytes, which is why PIH can be more prevalent in darker skins.

PIH can also be the end result of a variety of inflammatory conditions. PIH can have psychological implications, as discolouration and pigmentation changes can affect a persons' self-image.

Post Inflammatory Hyperpigmentation is not found within the epidermis like sun damage is; instead it is stagnant in the dermis. This is why exfoliation, chemical peels, or similar, will not work effectively to treat PIH, whereas treatments that reach the Dermal layer such as skin needling and 1064nm Q-switch Laser treatments will.

This stagnation of the pigment, along with the histiocytes ability to only clear up so much melanin at a time, is why PIH takes months to years to naturally clear up on its own.

The stimulation of the inflammation process can originate from both endogenous or exogenous sources:

Endogenous conditions

These conditions are internal and can cause irritation and inflammation in the skin which can impact pigmentation (PIH).

These conditions can include, but are not limited to:

Lichen planus - a chronic inflammatory skin condition affecting the skin and mucosal surfaces.
Psoriasis
Atopic dermatitis
Eczema
Acne vulgaris – can be both endogenous and exogenous

Actions like scratching and picking can also ensourage PIH along with the condition itself.