Differential Diagnosis for White Spots on the Face of a White Child with a Tan

• Single most likely diagnosis
  • Pityriasis versicolor (also known as tinea versicolor): This is a common fungal infection of the skin caused by Malassezia yeast, which is naturally found on the skin. It leads to discolored patches, typically on the chest, back, and sometimes the face, especially in individuals who have been tanning. The patches can be lighter or darker than the surrounding skin, making it a likely cause for white spots on a tanned face.
• Other Likely diagnoses
  • Idiopathic guttate hypomelanosis: A benign condition characterized by small, discrete, hypopigmented spots, often appearing on sun-exposed areas. It's more common in older adults but can occur in children, especially after sun exposure.
  • Post-inflammatory hypopigmentation: This can occur after any inflammatory process of the skin, such as eczema, psoriasis, or even a sunburn, leading to areas of lighter skin.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Vitiligo: An autoimmune condition leading to loss of pigment-producing cells (melanocytes), resulting in white patches. Although not immediately life-threatening, it can significantly affect a child's self-esteem and requires early intervention.
  • Tuberous sclerosis complex (with facial angiofibromas): A genetic disorder that can cause skin lesions, including angiofibromas which can appear as white or light spots on the face, among other systemic manifestations.
• Rare diagnoses
  • Piebaldism: A rare genetic condition characterized by the absence of melanocytes in affected areas of skin and hair, leading to white patches and often hair loss in these areas.
  • Waardenburg syndrome: A genetic disorder that can cause hearing loss, changes in eye color, and patches of light skin, among other symptoms. The skin manifestations can include hypopigmented patches.

Each of these diagnoses has distinct features and implications for management and prognosis, highlighting the importance of a thorough evaluation to determine the underlying cause of white spots on a child's face.