Differential diagnosis of female pattern hair loss

Other causes of diffuse hair loss may need to be excluded, particularly when the hair loss progresses rapidly

• drug induced hair loss (1)
  
  
• telogen effluvium most difficult differential diagnosis is from, particularly the chronic form
  • in some women with female pattern hair loss excessive shedding may be present for months or even years before there is an obvious reduction in hair density and occasionally it develops following typical acute telogen effluvium, suggesting that the shedding episode has revealed a pre-existing trait
    
    
• hyper or hypothyroidism
  • hair loss seen in hypothyroidism closely resembles female pattern hair loss and may indeed be identical
  • thyroid deficiency also causes a reversible increase in hair shedding (1,2)
    
    
• alopecia areata
  
  
• scarring alopecia (1)
  
  
• iron deficiency and poor diet (starvation/malabsorption/crash diet) (1)
  
  
• occasionally, systemic lupus erythematosus can also present in this way (2)

Reference:

• 1.Dinh QQ. Sinclair R. Female pattern hair loss: current treatment concepts. Clin Interv Aging. 2007;2(2):189-99.
• 2. Sinclair R, Wewerinke M, Jolley D. Treatment of female pattern hair loss with oral antiandrogens. Br. J. Dermatol. 2005; 152: 466-73.