Disorders of pigmentation — Clinical Case (Wikimedia Commons)

Diagnosis: Disorders of pigmentation

Tadpole with xanthochromism next to normal tadpoles. Clinical photograph sourced from Wikimedia Commons (CC BY-SA 4.0). Attribution: Chubbtub7.

Clinical Presentation

Hyperpigmentation: brown to gray-brown macules/patches in sun-exposed or previously inflamed areas. Hypopigmentation: well-demarcated depigmented or hypopigmented macules/patches. Wood's lamp examination enhances contrast.

Clinical History

Sun exposure history, medication use (minocycline, amiodarone), hormonal status (pregnancy, OCPs for melasma), prior inflammatory conditions, family history of autoimmune disease (vitiligo).

Treatment

Hyperpigmentation: sun protection, topical hydroquinone, retinoids, azelaic acid, chemical peels. Vitiligo: topical corticosteroids, calcineurin inhibitors, NB-UVB phototherapy, JAK inhibitors (ruxolitinib cream).

Differential Diagnosis

Melasma, Post-inflammatory hyperpigmentation, Vitiligo, Pityriasis alba, Tinea versicolor, Drug-induced pigmentation

Key Learnings

Wood's lamp examination helps classify pigmentary disorders — epidermal pigment enhances under Wood's lamp while dermal pigment does not. Sun protection is essential for all pigmentary disorders.

Tags: pigmentation, melasma, hyperpigmentation, hypopigmentation