Post-Inflammatory Hyperpigmentation and Scar Management in a Teen Patient: A Case from Katy, Texas

by: Dr. Caroline Vaughn

Case Overview

A 15-year-old female presented to Village Dermatology in Katy, Texas, accompanied by her mother, for evaluation of discoloration and scarring on both knees. The scars, moderate in severity, had been present for several years and were noted to be darkening over time.

The patient reported no recent trauma or new symptoms but expressed cosmetic concern over persistent pigmentation. She had been using vitamin E oil with minimal improvement.

Clinical Examination

A focused examination was performed on the right and left lower legs, including both knees.
The patient appeared well-developed, alert, and in no distress. A dermatoscope was used during evaluation.
Findings revealed ill-defined hyperpigmented patches on both knees, consistent with post-inflammatory hyperpigmentation (PIH) secondary to prior trauma.

Assessment and Plan

1. Post-Inflammatory Hyperpigmentation (L81.0)

PIH occurs when excess melanin is produced following skin injury or inflammation, leading to dark spots or discoloration. The knees and legs are particularly prone to prolonged pigmentation due to thicker skin and slower healing.

Management Plan:

• Topical Tretinoin 0.025% Cream: Apply to affected areas 2–3 nights weekly, increasing to nightly as tolerated

• Sun Protection: Use broad-spectrum sunscreen SPF 30+ and protective clothing daily

• Moisturizers: Apply CeraVe moisturizing cream and Dove Sensitive Skin wash to maintain barrier repair

• Scar Management: Begin silicone gel or silicone sheets for smoothing texture and improving discoloration

Counseling:
The patient and her mother were educated on the slow nature of pigment fading and the importance of consistency and sun avoidance. Results may take months to years, depending on depth and skin tone.
Potential side effects of tretinoin, such as dryness or mild irritation, were reviewed, and the patient verbalized understanding.

2. Scar (L90.5)

Scars on both knees were consistent with post-traumatic remodeling—flat, stable, and showing hyperpigmentation but no keloid or hypertrophic features.

Recommendations:

• Continue silicone gel and SPF 30+ sunscreen to prevent further darkening

• Keep fresh wounds moisturized with Vaseline or Aquaphor to minimize scarring

• Monitor for any raised or discolored changes, which could indicate hypertrophic scarring

Counseling:
Discussed that scars are permanent skin changes but often fade and flatten over time. Encouraged patience and consistent skin care for optimal cosmetic improvement.

Discussion

Post-inflammatory hyperpigmentation is a common cosmetic concern in adolescents, particularly in darker skin types and on knees, elbows, or legs following trauma. The combination of tretinoin, moisturizers, and strict sun protection provides safe, gradual improvement.
At Village Dermatology, patients in Katy and Houston, TX benefit from evidence-based care focused on both medical and cosmetic skin restoration. Early dermatologic intervention helps prevent chronic discoloration and improves self-confidence in younger patients.

Conclusion

This case highlights the successful management of knee hyperpigmentation and scarring in a teenage patient through gentle retinoid therapy, silicone scar treatment, and sun protection.
For patients in Katy or Houston, Texas, Village Dermatology offers comprehensive care for pigmentation, scars, and skin health across all ages.