Start by Naming What You're Actually Treating
Recorded live at the Elevate Derm Summer Conference in Park City, Utah, hosts Shanna Miranti and Buchi Neita sit down with Boston-area dermatology PA Eileen Cheever, who has nearly 18 years in practice, to tackle one of the most frustrating visits in the clinic. Cheever's first point is a level-set: when clinicians say 'pigmentation,' they aren't just talking about melasma. Much of what walks through the door is post-inflammatory hyperpigmentation (PIH) driven by dermatitis, psoriasis, or acne, and the majority of what's seen in clinic is acquired.
Once you identify a lesion as acquired, Cheever's next fork in the road is whether the pigment is epidermal or dermal. Epidermal pigmentation typically involves melanin and melanocytes and reads as tan or brown; dermal pigmentation involves macrophages, melanin, or hemosiderin and carries more of a blue or gray hue. That distinction isn't academic — it steers whether topicals and cosmeceuticals will be enough or whether procedural interventions will be needed. Cheever also reminds listeners that many pigmentation patients present with a mixed picture.
Put the Wood's Lamp Back to Work
Cheever's most practical chair-side tip is to know where your Wood's lamp is and to use it. If the pigment enhances under the lamp, it's typically epidermal; if it doesn't enhance, it's typically dermal. Her workflow trick: plug the lamp in, give it a couple of minutes to warm up while you see the next patient, then come back and examine.
Beyond the diagnostic value, she frames the Wood's lamp as a relationship tool — it signals to patients that you care enough to investigate a condition that carries real stigma and anxiety. Miranti adds that newer dermatoscopes now come with a built-in Wood's lamp feature, and predicts plenty of listeners will be plugging theirs in when they get home.
The Limits of the Traditional Toolbox
Before turning to new options, Miranti asks Cheever to review the familiar agents: kojic acid, azelaic acid, resorcinol, and of course hydroquinone. Patients know hydroquinone well and often request it, and Cheever acknowledges it can be useful with proper supervision and a motivated patient — but she is candid about the risks.
Two hydroquinone concerns lead her list. Ochronosis, where patients develop a deepening or darkening of the treated area — more pigmentation from the treatment itself. And because hydroquinone is cytotoxic to melanocytes, the formation of orthoquinone derivatives can kill those cells and leave bright white patches of leukoderma. Cheever notes that kojic acid can also cause pigmentation issues, and case reports describe azelaic acid accentuating pigmentation. The takeaway: these agents can be effective, but they come with tolerability issues, warnings, and real risk.
Thiamidol: A Human Tyrosinase Inhibitor Arrives in the U.S.
The centerpiece of the conversation is thiamidol, a product used overseas for years with substantial research behind it. Cheever walks through the mechanism: tyrosinase is the rate-limiting enzyme in the pigmentation cascade, and thiamidol is a tyrosinase inhibitor. The key differentiator, she explains, is that many prior products were derived and tested against mushroom-based tyrosinase, whereas thiamidol has been studied and found effective against human tyrosinase — and it works without being cytotoxic to melanocytes, offering good efficacy with a strong safety profile.
For a patient treating melasma or acne-related PIH, Cheever describes counseling them to apply the thiamidol serum in the morning to the affected areas followed by sunscreen, then again in the evening followed by their nighttime product.
On the halo effect that plagues hydroquinone, Cheever points to a study in acne PIH conducted in patients with skin of color (Fitzpatrick V–VI, the population that most struggles with acne PIH). Thiamidol was superior at fading the marks, and importantly, investigators saw no lightening or haloing of the skin surrounding the treated pigmentation.
Beyond Melasma and Toward Prevention
Cheever urges APPs to widen their thinking beyond the reflex that thiamidol is 'just a melasma product.' She cites efficacy in melasma, improved solar lentigines, and improved acne-related PIH marks.
Most intriguing to the hosts is a preventative signal: in one study, participants who used a thiamidol-containing product twice daily for three weeks before narrowband UVB exposure did not develop the accentuation of hyperpigmentation seen in the vehicle group. That opens the door to using the serum as maintenance for patients terrified their melasma will return-a meaningful shift for a condition that can plague patients for decades.
Cheever closes with her holistic approach to sun protection: no matter the diagnosis, she counsels sunscreen, hats, and seeking shade, and helps patients identify their triggers-including heat-so they can mitigate exposure.