Card Test as a Simple Method to Diagnose Short Anagen Syndrome

Case Presentation

In short, anagen hair syndrome (SAS), the hairs are short, fine, and sparse since birth even if the typical patient presents to a medical consultation around the age of 5–6 years. Parents often complain the hair doesn’t grow long and that they have never been cut. The presence of short hair shafts is due to a short duration of the anagen phase. Hair shafts have also been described as thinner and in telogen phase. The clinician should rule out congenital hypotrichosis, loose anagen hair syndrome, telogen effluvium.

Teaching Point

We propose the card test as a quick and inexpensive method to help in the diagnosis of SAS. Tufts of hairs are placed on a card (Figure 1A) and observed with a dermoscope at 20X magnification: thin hair shafts with pointed tips are proof the hairs have never been cut (Figure 1B). This test can be done even without pulling the hair out of the scalp.

Figure 1.

(A) The card test showing how a tuft of short hairs should be placed on a card before observing them with a dermatoscope. (B) Multiple and exclusively pointed tips, showing the short shafts have never been cut, and after cut, are easily seen with a 20X magnification.