A Case Report on The Use of Topical Cysteamine 5% Cream in the Management of Refractory Post-Inflammatory Hyperpigmentation (PIH) Resistant to Triple Combination Cream ( hydroquinone, topical corticosteroids and retinoids)

Background: Post-inflammatory hyperpigmentation (PIH) occurs as a result of different inflammatory dermatoses and exogenous factors in individuals with darker skin types. With current skin lightening treatments, there are concerns about irritation leading to worsening of their underlying inflammatory skin condition or worsening of PIH.

Case: A 20-year-old woman with Fitzpatrick skin type (FST) V presented with facial hyperpigmented patches since childhood following an intermittent erythematous, pruritic facial rash. Skin biopsy confirmed PIH secondary to possible burnt-out morphea. Treatment with topical adapalene 0.1% gel and triple combination cream (containing hydroquinone, topical corticosteroids and retinoids) proved unsuccessful. Treatment with cysteamine 5% cream over 4 months resulted in significant improvement with a reduction in the melanin index.

Discussion: The current recommendation for first-line treatment in PIH is hydroquinone or triple combination cream containing hydroquinone, which can be associated with significant short- and long-term side effects. Cysteamine 5% cream is one of the latest cosmetic skin lightening products. It is hypothesised that cysteamine reduces melanin production by inhibiting key melanogenic enzymes required in melanogenesis. Its efficacy and tolerability have been demonstrated in two randomised controlled trials against placebo in patients with melasma. This report demonstrates a successful use of cysteamine 5% cream in a patient with chronic severe PIH.

Keywords: cysteamine; hyperpigmentation; management; post-inflammatory hyperpigmentation.