Jennifer Soung, MD, and Mona Shahriari, MD, discuss diagnosing psoriasis in diverse skin tones and why severity scores overlook dyspigmentation.
Soung, a psoriasis specialist, said her interest in the condition began in medical school through research with Mark Lebwohl, MD, and grew alongside an early focus on the immunology behind biologic therapies. She trained in New York City specifically to gain exposure to a wide range of skin tones and racial and ethnic backgrounds, and she noted a preference for the term "diverse skin tones" over "skin of color," since disease presentation is ultimately a matter of skin biology rather than race or ethnicity alone.
Shahriari asked Soung for visual diagnostic tips clinicians could apply in practice. Soung explained that erythema in psoriasis often appears less bright red in more pigmented skin, sometimes presenting as a subtle or violaceous tone that can lead physicians to underestimate disease severity, an effect that can persist even in clinical photographs taken under standard lighting. Plaques may also be thicker, and the classic silvery scale associated with psoriasis can instead appear micaceous or keratotic.
Itch tends to be more pronounced in some patients, and Soung described a case in which excoriation from itching made a psoriasis plaque resemble chronic atopic dermatitis. She recommended biopsy in cases of diagnostic uncertainty, along with dermoscopy, which Shahriari noted can use polarized light to help distinguish erythema from non-erythema and pigment from non-pigment change. Both physicians agreed that a poor response to a highly effective biologic or advanced systemic therapy should prompt clinicians to revisit the diagnosis.
Both speakers pointed to post-inflammatory hyperpigmentation and hypopigmentation as a major, and frequently overlooked, part of the patient experience. Shahriari said patients often report that a biologic has not worked even after plaques have fully cleared, because residual dark or light marks remain visible to them. Soung noted that standard tools such as the Psoriasis Area and Severity Index and the Physician Global Assessment or Investigator Global Assessment were developed using white skin and do not account for dyspigmentation, raising the question of whether these measures, or clinical trial endpoints more broadly, should be revised to reflect that aspect of disease burden.
Shahriari and Soung agreed that delayed or incorrect diagnosis compounds harm well beyond prolonged itching and pain. Soung described the case of a Vietnamese Middle Eastern ICU nurse who had been treated for atopic dermatitis with an interleukin-4/13 inhibitor for a year; the medication controlled her itch but not her skin lesions, and after a lapse in treatment, a well-demarcated silvery plaque on an area she could no longer scratch pointed to a psoriasis diagnosis that had been missed.
Soung said consequences of delayed diagnosis in this population can extend to psychosocial and financial harm, including job loss in cases where visible plaques affect a patient's career. Shahriari said the broader lesson she shares with residents is to broaden their visual expectations of disease presentation, rather than relying on textbook descriptions built around a narrower range of skin tones.
Editor's note: This summary was edited with the help of AI tools.
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