Differential Diagnosis for Patchy Beard

• Single most likely diagnosis
  • Alopecia areata: This is an autoimmune condition that can cause patchy hair loss on the scalp, beard, or other areas of the body. It is a common cause of patchy beard and often presents with well-defined patches of hair loss.
• Other Likely diagnoses
  • Androgenetic alopecia: Also known as male pattern baldness, this condition can cause thinning and patchy hair loss, including in the beard area. It is influenced by genetics and hormonal factors.
  • Tinea barbae: A fungal infection of the beard area, which can cause patchy hair loss, redness, and itching. It is more common in individuals who share razors or have poor hygiene.
  • Pseudofolliculitis barbae: An inflammatory condition caused by ingrown hairs, which can lead to patchy hair loss, especially in individuals with curly hair who shave frequently.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Sarcoidosis: A systemic disease that can cause skin and hair lesions, including patchy beard loss. It is essential to consider this diagnosis due to its potential for serious systemic complications.
  • Lupus: Systemic lupus erythematosus (SLE) can cause hair loss, including patchy beard loss, as part of its wide range of symptoms. Early diagnosis is crucial due to the potential for severe organ damage.
• Rare diagnoses
  • Discoid lupus erythematosus: A chronic skin condition that can cause scarring hair loss, including in the beard area. It is less common than SLE but still important to consider.
  • Lichen planopilaris: An inflammatory condition that can cause patchy hair loss, including in the beard area, due to the destruction of hair follicles. It is relatively rare but can lead to permanent hair loss if not treated.