Lichen planus pigmentosus and other pigmentary disorders
Differential diagnosis and tips for managing less-common pigmentary disorders in patients with skin of colour (1,300 words, 6 minutes)
There are a range of pigmentary disorders that can impact patients with skin of colour. At Skin of Color Update 2022 in New York, Dr. Heather Woolery-Lloyd provided clinical pearls and diagnostic tips for some, including progressive macular hypomelanosis and lichen planus pigmentosus.
Dr. Woolery-Lloyd is the Director of the Skin of Color Division at the University of Miami Miller School of Medicine, in Miami.
Lichen Planus Pigmentosus
Lichen planus pigmentosus can be confused with ashy dermatosis, also known as erythema dyscromicum perstans, said Dr. Woolery-Lloyd, because both conditions are lichenoid reactions that involve pigment being deposited in the upper dermis.
Differential diagnosis for lichen planus pigmentosus:
Mostly found on the face and neck, and less commonly on the forearms
Tends to appear when a patient is in their 30s or 40s
More common in female patients
Lesions first appear as small, poorly-defined oval or round macules. They later tend to grow together into large pigmented areas that vary in colour from slate grey to brownish-black
Ashy dermatosis is more often seen on the trunk and extremities, and the lesions have a ring of erythema
Dr. Woolery-Lloyd said lichen planus pigmentosus can be challenging to treat, but that she had a patient who responded well to six months of azelaic acid 20% mixed with hydrocortisone 2.5%.
Progressive Macular Hypomelanosis
Has been described in young people of all races with darkly pigmented skin
Lesions are asymptomatic, poorly-defined, non-scaly round spots on the trunk
Lesions tend to grow together around the midline of the body, rarely spreading to the head or neck, or the ends of the limbs
Pigment loss is not post-inflammation
While progressive macular hypomelanosis tends to progress slowly over decades, the lesions usually disappear by the time the person reaches mid-life, Dr. Woolery-Lloyd said.
Physicians should distinguish this condition from pityriasis alba and tinea versicolor. Dr. Woolery-Lloyd said that progressive macular hypomelanosis is suspected to be caused by P. acnes bacteria producing a molecule that interferes with the creation of melanin.
She said some patients experience an improvement with topical antimicrobials and oral doxycycline.
Bottom line: Physicians should be aware of progressive macular hypomelanosis and lichen planus pigmentosus in patients with richly pigmented skin. Treatment of these disorders can be challenging, but some approaches can produce improvements.
From the literature on pigment disorders in skin of colour
Human dermal fibroblast-derived extracellular matrix reduces post-inflammatory hyperpigmentation after fractional carbon dioxide laser facial resurfacing in Asians
This double-blind, randomized, vehicle-controlled, split-face study was conducted by researchers in South Korea. They recruited 15 participants with features of facial skin aging and treated the patients with a single session of fractional carbon dioxide laser, followed by the application of either a human dermal fibroblast-derived extracellular matrix or a placebo.
Of the 15 recruited patients, 14 (mean age 45.1 ± 9.7 years) completed the study.
Post-inflammatory melanin change was significantly lower in the active group than in the control group at week 12 (p<0.05). The researchers observed a transient increase in erythema level at week four in the control group, and the change in the erythema level was greater in the control group than in the active group (p=0.014).
The researchers saw no significant differences between the groups in dermal density, texture, transepidermal water loss, marionette lines, and nasolabial folds. They didn’t report any treatment-related adverse events.
Post-inflammatory hypopigmentation: Review of the etiology, clinical manifestations, and treatment options
The authors of this review note that post-inflammatory hypopigmentation is more prominent in patients with skin of colour and leads to significant cosmetic and psychosocial implications.
Therefore, they assembled this review to support a thorough understanding of the epidemiology, patient history, physical exam findings, and clinical features of post-inflammatory hypopigmentation.
“It is also important to understand the various therapeutic approaches available and the efficacy of these options, which will inform providers to choose the appropriate therapy for patients,” they write.
The authors note there is a lack of specific validated tools to measure post-inflammatory hyperpigmentation.
Picosecond neodymium-doped yttrium-aluminum-garnet laser therapy for pigmentation due to lichen planus pigmentosus in a patient with skin of colour
This paper describes the case of a 73-year-old female with skin of colour and lichen planus pigmentosus treated with a picosecond laser.
The patient underwent 10 total treatments of the full face with 1,064 nm wavelength, with approximately one month between treatments. The physician started the patient on topical hydroquinone 8%, kojic acid 10%, and vitamin C 5% triple therapy at the time that laser therapy to prevent dyspigmentation, but this was discontinued after the third session due to irritation.
The physicians observed moderate improvement after 10 sessions but pigmentation persisted. After testing a 785 nm laser on a spot without causing adverse events, the patient was treated four more times at the shorter wavelength, which led to a significant improvement in pigmentation. The authors write that the most notable improvements were a decrease in pigmentation across the nose and blending of a blending of the line between the lesions and normal skin. While there was mild swelling after each treatment, this was managed with ice packs. The physicians also prescribed a hydrocortisone 2.5% cream twice a day for three to five days after treatment. The patient did not develop any dyspigmentation or scarring.
Reliability assessment and validation of the post-acne hyperpigmentation index (PAHPI) in a population from sub-Saharan Africa in Senegal
This study was conducted to validate a US-developed post-acne hyperpigmentation index (PAHPI) in patients with skin type VI from sub-Saharan Africa.
Researchers recruited 21 patients from Dakar, Senegal, aged 17 to 55 years who had hyperpigmentation secondary to acne. The patients were permitted to continue the use of acne treatments and skin-bleaching agents. Four trained dermatologists rated the patients using PAHPI.
They found PAHPI scoring demonstrated excellent reliability both between and within raters. Correlations between narrow-band reflectance spectrophotometer measurements of pigmentation and PAHPI scores also showed moderate to substantial agreement.
VIDEO: Body Hyperpigmentation | Skin Of Colour | Brown Or Black Skin—Dr. Vanita Rattan
At the intersection of skin and society
A new exhibition of photographs and other media celebrating Black identities, culture, and community has opened at the Art Gallery of Ontario in Toronto and will run until May 2024.
Titled Feels Like Home, the exhibition is the first-ever museum installation by the creative agency Sunday School.
According to a press release from the gallery, Sunday School was founded by Nigerian-Canadian Creative Director Josef Adamu in 2017.
The exhibition features photographs from three recent series: The Hair Appointment (2018), Ten Toes Down (2021) and Jump Ball (2019–ongoing).
The images by Jeremy Rodney-Hall and the select video excerpted from The Hair Appointment (2018) offer a poignant depiction of hair as a cultural signifier of Black womanhood.
Featuring a Black ballerina posing in her own home, the series Ten Toes Down (2021) photographed by Kreshonna Keane, builds on the creative work Sunday School undertook with the British clothing manufacturer Freed of London, one of the first brands to mass produce and market skin tone pointe shoes for Black, Asian, and mixed-race dancers.
First published in 2019, Jump Ball is an ongoing series exploring the relationship between basketball and African Diasporic communities. Jump Ball: Toronto photographed by Toronto’s O’shane Howard, features young men in both traditional African attire and street-style clothing posed on the basketball courts of St. Jamestown.
This week
June is Caribbean-American Heritage Month in the US
June is National Indigenous History Month in Canada
June 1 is National Skincare Education Day in the US
Something to think about in the week ahead…
Anne Morrow Lindbergh, US author, 1906 to 2001
Next week
In a talk at the 8th annual Skin Spectrum Summit, Dr. Jaggi Rao provides recommendations for the safe use of thermal lasers in darker skin types for reducing large pores, managing melasma, and other conditions.
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An essay from Dr. Saima Ali (Burnaby, B.C.) submitted to the 2022 Dermatology Industry Taskforce on Inclusion, Diversity and Equity (DiTiDE) short essay contest. Dr. Ali wrote on the challenge of restoring the confidence of patients with skin of colour with the practice of dermatology.
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