When brown patches are not melasma
“Not every brown patch on the face is melasma, and not every white patch is vitiligo.” Dr. Andrew Alexis on diagnoses not to miss. (770 words, 3.5 min read)
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In a presentation titled “Diagnoses Not to Miss” at skin spectrum summit in Toronto, Dr. Andrew F. Alexis sorted through several cases in which his patients exhibited pigmentation symptoms that could easily be misinterpreted as more common diseases at first glance due to their fairly standard appearance.
In some cases, skin hyperpigmentation can be brought on by unusual skin-care regimens or reactions to other therapies, he said.
“When one is presented with symmetrical brown patches on the face, the diagnosis is usually melasma, but not always.”
He outlined some cases in which these brown patches turned out to be something different than expected.
Dr. Alexis discussed a case involving a 53-year old African-American woman with brown patches on her face, which he said is a widespread complaint. He described her patches, which appeared on the cheek and temple, as brown with a purplish-grey hue. She also had a past medical history of hypertension, for which she was prescribed diltiazem.
“What else can it be?” he asked the audience. It turns out that diltiazem triggered a photodistributed lichenoid drug eruption, he said.
“After identifying the causative agent — diltiazem in this case — discontinuing it and switching to a chemically unrelated antihypertensive, she got better,” he said.
He noted that this purplish-grey photodistributed lichenoid drug eruption could also be caused by therapies such as antimalarials, thiazide diuretics, fursemid, ethambutol and tetracycline.
“When you see dark patches on the face that aren’t quite brown but [are] more greyish blue or lichenoid looking, consider photodistributed lichenoid drug eruption,” he said.
He used other examples to explain the process he went through to find the correct diagnosis.
One case involved a woman with post-inflammatory hyperpigmentation brought on by months of harsh scrubbing of her facial area “to even her skin tone,” said Dr. Alexis.
“She was trying to treat hyperpigmentation but induced hyperpigmentation from her very irritating skin-care regimen,” he said.
He noted a second case was a patient with lichen planus pigmentosus, which tends to be in a photodistributed area, he said. Characteristics include bluish-grey pigmentation on the face, head and neck.
He used these cases as a lesson to the audience to be thorough in investigating the causes of a patient’s symptoms.
The takeaway: When thinking about the common things we see in patients of colour, it is easy to get into a little bit of a rut. Not every brown patch on the face is melasma, and not every white patch is vitiligo,” said Dr. Alexis.
FROM THE LITERATURE ON DIFFERENTIAL DIAGNOSES
The role of patch testing with Indian cosmetic series in patients with facial pigmented contact dermatitis in India
A study on pigmented contact dermatitis in Indian individuals emphasized patch testing's importance to identify any allergens implicated in the condition. The researchers looked at 38 biopsies that showed a mix of lichenoid and spongiotic features.
Pembrolizumab-induced lichenoid dermatitis in a patient with metastatic cancer of unknown primary
A case study of a 72-year old man with metastatic carcinoma examined his lichenoid dermatitis, which occurred due to treatment with pembrolizumab. The researchers found that discontinuation of the immunotherapy was the best option.
Frequency of different types of facial melanoses and assessment of their effect on health-related quality of life
A recent study has determined how much facial melanoses can affect the quality of life (QoL) of patients. Investigators found that QoL was most impaired for patients with melasma with steroid-induced rosacea-like dermatitis with a Dermatology Life Quality Index (DLQI) score of 13.54 ± 1.30. Participants with ephelides were found to have the lowest QoL impairment.
VIDEO: How facial melasma affects QoL
AT THE INTERSECTION OF SKIN AND SOCIETY
Bollywood movies show an ideological tendency to favour fairer skin, according to a recent AI study conducted by researchers at Carnegie Mellon University. Also, the study found that protagonists of the films tend to be upper-caste, according to an article by Vice Media. The researchers taught an AI system to scan decades worth of Bollywood movies for phrases and words that indicate preferences toward one skin type or another. According to the report, the AI model was also used to evaluate Hollywood movies and found similar, though less pronounced, results. Read the full article here.
This Week
Thursday, March 18 and Saturday, March 20, Indigenous Skin Spectrum Summit
Monday, March 15 to Sunday, March 21 Brain Awareness Week
Friday, March 19 is World Sleep Day
Something to think about during the week ahead…
Next Week
Dr. Haneef Alibhai outlines safe, effective aesthetic treatments for patients with skin of colour.
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