Differential Diagnosis of Vitiligo

When considering the differential diagnosis for vitiligo, it's crucial to evaluate various conditions that could mimic its clinical presentation. The following categorization helps in systematically approaching the diagnosis:

• Single Most Likely Diagnosis

  • Vitiligo itself is often the most likely diagnosis when characteristic depigmented patches are present, especially if they are symmetric and involve the face, hands, or areas around body orifices. The presence of Koebner phenomenon (appearance of new lesions at sites of trauma) and leukotrichia (white hair) within the patches can further support this diagnosis.

• Other Likely Diagnoses

  • Pityriasis alba: A condition that presents with hypo-pigmented patches, often with fine scales, typically on the face, and is more common in children. It's distinguished from vitiligo by the presence of scaling and less distinct borders.
  • Post-inflammatory hypopigmentation: This occurs after inflammatory skin conditions like eczema, psoriasis, or dermatitis, where the skin appears lighter than the surrounding areas due to inflammation-induced damage to melanocytes.
  • Idiopathic guttate hypomelanosis: Characterized by small, discrete, hypo-pigmented macules, typically on sun-exposed areas, without the inflammatory history or scaling.

• Do Not Miss Diagnoses

  • Piebaldism: A rare genetic condition characterized by congenital depigmented patches, often on the forehead, scalp, and chest, which can be mistaken for vitiligo. It's crucial to distinguish because of its genetic implications.
  • Waardenburg syndrome: Another genetic disorder that includes depigmentation of the skin and hair, along with deafness and other developmental anomalies. Missing this diagnosis could lead to overlooking associated hearing loss and other systemic issues.
  • Chemical leukoderma: Caused by exposure to certain chemicals that destroy melanocytes, leading to depigmentation. Identifying this condition is critical for removing the causative agent and preventing further damage.

• Rare Diagnoses

  • Nevus depigmentosus: A congenital condition presenting as a single, well-defined, hypo-pigmented patch, which can be mistaken for a segmental form of vitiligo.
  • Tuberous sclerosis: A genetic disorder that can present with hypo-pigmented macules (ash leaf spots), among other systemic manifestations. Recognizing these skin findings can lead to the diagnosis of this complex condition.
  • Progressive macular hypomelanosis: A condition of unknown etiology, characterized by hypo-pigmented macules that progress over time, often on the trunk, which can be confused with vitiligo due to its progressive nature.