Patient with PIE                                                            Patient with PIH

Postinflammatory erythema (PIE) and postinflammatory hyperpigmentation (PIH) are common conditions in patients after an outbreak of acne and rosacea.¹ The diagnoses can be confusing to patients who are unfamiliar with the terminology. You can help your patients along their treatment journey by ensuring they understand the nature of their conditions and how the healing process will work (Fig. 1):

• PIE and PIH are distinct conditions¹
• PIH is more common in patients with darker skin (Fitzpatrick types IV, V, and VI) and is caused by changes in the colors of pigment cells, concentrating dark pigment in one area (hyperpigmentation) ^1,2
• PIE refers to residual and localized erythema (redness) and is a type of dyspigmentation that presents as discrete erythematous macules most often in patients with lighter skin (Fitzpatrick types I, II, III)¹
• PIE is often present after any type of active skin inflammation (ie, not just acne and rosacea). It is a different condition than the persistent background erythema caused by rosacea or the postoperative erythema associated with certain acne scarring treatments¹
• PIE and PIH are conditions that may resolve over time; however, PIH can sometimes take years to clear and is especially burdensome for those with darker skin^1,3

Although inflammation is the root cause of both PIE and PIH, treating each condition requires a separate approach depending on the underlying skin disease and the patient’s skin type. ^1,3,4 As with all patients, a conversation about treating their PIE and PIH should begin with listening to their concerns and obtaining a thorough history of their conditions.^1-3  

A guide to PIE and PIH is included below that can help patients better understand their condition.

Figure 1. Quick Guide to the Differences and Similarities Between PIE/PIH^1,2

References:

1.     Bae-Harboe YS, Graber EM. Easy as PIE (Postinflammatory Erythema). J Clin Aesthet Dermatol. 2013;6(9):46-47.

2.     Davis EC, Callender VD. Postinflammatory hyperpigmentation: a review of the epidemiology, clinical features, and treatment options in skin of color. J Clin Aesthet Dermatol. 2010;3(7):20-31.

3.     Lawson CN, Hollinger J, Sethi S, et al. Updates in the understanding and treatments of skin & hair disorders in women of color. Int J Womens Dermatol. 2017;3(1)(suppl):S21-S37. doi:10.1016/j.ijwd.2017.02.006

4.     Mathew ML, Karthik R, Mallikarjun M, Bhute S, Varghese A. Intense pulsed light therapy for acne-induced post-inflammatory erythema. Indian Dermatol Online J. 2018;9(3):159-164. doi:10.4103/idoj.IDOJ_306_17