5 mins
Post-inflammatory hyperpigmentation following lichen planus
Dr Selina Ahmed discusses a recent dermatology case study
DR SELINA AHMED
Dr Selina Ahmed earned her degrees in medicine and surgery from the esteemed University of Manchester in 2010. As a distinguished general practitioner specialising in dermatology, she is recognised for her exceptional patient care and contributions to medical education. Dr Ahmed’s dedication to education is underscored by her previous role as a clinical lead lecturer and trainer for Acquisition Aesthetics, while operating her own successful skin clinic, Dr Selina Clinics, in London.
Post inflammatory hyperpigmentation (PIH) is a prevalent skin condition, particularly affecting individuals with skin of colour. It is a cutaneous skin disorder that is more common in individuals with Fitzpatrick skin types III to VI. PIH is a chronic condition that can take several months, sometimes years, to resolve.1
PIH occurs as a result of inflammation or injury to the skin, triggering the release of cytokines that stimulate melanin production and dispersion within the epidermis.2 In conditions such as lichen planus, the basal layer of the epidermis can be affected where melanin pigment is released and subsequently sequestered by macrophages in the papillary dermis, a phenomenon known as dermal melanosis or pigment incontinence.3
PIH commonly arises from conditions like acne, lichen planus, contact dermatitis, mechanical trauma, and various skin-directed treatments such as dermabrasion, chemical peels, and laser surgery.2 PIH secondary to lichen planus typically manifests as hyperpigmented macules or flat-topped papules, often exhibiting a violaceous hue characteristic of the underlying lichenoid inflammation. These pigmented lesions are frequently localised to areas affected by lichen planus lesions, such as the flexural surfaces, wrists, ankles, and genitalia. The mouth can also be commonly affected, which is important to exclude at presentation, due to the long-term risk of oral lesions developing into squamous cell carcinoma.
A range of treatment options exists for cutaneous PIH, including topical therapies, chemical peels, and laser treatments, though their efficacy varies among individuals.2 Treatments offered on the NHS will vary compared to those that are available privately, which is an important note for this case study.
While many cases of PIH will resolve naturally, the process can be lengthy, sometimes spanning months or even years, and in certain instances, the pigmentation changes may become permanent.1 The persistence of PIH can significantly impact patients’ psychological well-being and quality of life, which is important to manage alongside the dermatological complaint.
PATIENT A
Presenting complaint: A 42-year-old female presented to the NHS community dermatology clinic in October 2023 with post inflammatory hyperpigmentation following a diagnosis of suspected cutaneous lichen planus made by her GP.
Past medical history: Nil
Drug history: Nil
Social history: Non-smoker, occasional alcohol use, no known drug allergies
History of presenting complaint: 42-yearold female with Fitzpatrick skin type V started to develop pruritus over her lower legs and over the ventral surfaces of her wrists during June 2023. She presented to her GP who prescribed her an antihistamine: Fexofenadine 180mg to be taken daily and advised to use regular emollients, with the initial diagnosis thought to be irritant contact dermatitis. At this stage no clear rash had developed. Over the next few weeks, the pruritus continued, and went on to develop violaceous flattopped papules over her lower legs and ventral surfaces of her wrists. These were largely symmetrical. She was subsequently referred to the NHS dermatology clinic.
Patient Apresented to the dermatology clinic to see me, some four months after the presentation of the rash, confirming a diagnosis of lichen planus. The pruritis was infrequent at this stage. Images on her phone from previous months confirmed the diagnosis of lichen planus, as they are very characteristic. On darker skin types, active lichen planus is not as red and more of a darker purple.
There was significant post inflammatory hyperpigmentation over the affected areas. The areas over her wrists which were very light brown macules didn’t bother her so much. However, the surface areas over her anterior lower legs were causing her great distress emotionally where large areas were covered in dark brown macules and patches.
TREATMENT APPROACH
Usually, management of the patient’s condition would commence with targeted therapies aimed at controlling the lichen planus activity, including topical corticosteroids and oral steroid treatment. At presentation to the dermatology clinic, the patient’s lichen planus was relatively inactive but she was very distressed by the PIH that had remained.
She was initially prescribed betnovate cream to relieve some of the pruritus that was remaining, on a weaning regime over three weeks. At her follow up appointment, the pruritus had all resolved but she was deeply distressed by the pigmentation. At this stage, Pigmanorm cream was prescribed, which contains fluocinolone acetonide 0.01%, hydroquinone 4%, and tretinoin 0.05% and she was advised to use this once daily. Given her predisposition to PIH, she was instructed to apply the cream to a small area first to ensure there was no irritation and if tolerated could apply to the remaining affected areas. Regular SPF with a minimum factor of 30 was emphasised to avoid the pigmented areas from becoming darker.
TREATMENT OUTCOMES
At her follow-up three months after applying the Pigmanorm cream, she felt there was only very mild improvement in the colour of the patches but did feel the patches were now smooth and not raised. I signposted her to Changing Faces, a UK based charity which offer a skin camouflage service to cover up the areas with body make-up.
Managing Patient A’s expectations was key here and discussing that the deeper layers of her skin which are affected by the hyperpigmentation, can take several months to years to lighten up. Further treatment such as lasers, peels or using other tyrosinase inhibitors are available privately, but there are varying degrees of success for PIH5 and carry the risk of worsening her PIH. In some instances, PIH never goes away.
DISCUSSION
Patient A was not able to afford private treatments for her PIH and had only mild epidermal improvement to her skin with the Pigmanorm cream. However, laser-based pigment treatments, including fractional non ablative lasers and IPL treatments have varying degrees of success in managing PIH due to deeper dermal skin involvement.5 Supporting patients and understanding the psychological effects of their skin conditions is essential, while realistically managing their expectations.
CONCLUSION
Post-inflammatory hyperpigmentation following lichen planus poses significant challenges in dermatology practice, necessitating a comprehensive and individualised treatment approach. Treating the initial inflammation promptly can reduce the risk and extent of subsequent post inflammatory hyperpigmentation. Treatments available on the NHS and those available privately will be different with varying degrees of success.
REFERENCES
1. Lawrence L, Aboud K. Post Inflammatory Hyperpigmentation. StatPearls Publishing LLC. 2024, October 3
2. Davis E, Callender V. Postinflammatory Hyperpigmentation AReview of the Epidemiology, Clinical Features, and Treatment Options in Skin of Color. J Clin Aesthet Dermatol. 2010 Jul; 3(7): 20–31
3. Ngan V. December 2015. Postinflammatory Hyperpigmentation. Dermnetnz. Accessed 25 April 2024. (https://dermnetnz.org/topics/postinflammatory-hyperpigmentation)
4. Chen J, Oakley A, Liu Jing. Lichen Planus. Dermnetnz. Accessed 28 April 2024. (https://dermnetnz.org/topics/lichen-planus)
5. Arora P, Sarkar R, Garg VK, Arya L. Lasers for treatment of melasma and post-inflammatory hyperpigmentation. J Cutan Aesthet Surg. 2012 Apr;5(2):93-103.