Sir,
We thank the authors for their interest shown in the article “Use of ball point pen in the diagnosis of physical urticarial”.[1]
We agree with the authors that the pressure of the hand varies from person to person.[2] This is a simple test to detect mild, moderate, and severe dermographism in office practice of a busy dermatologist.
A new instrument named Fric test has been devised by the Department of Dermatology of the Charite Hospital, Berlin, Germany. The purpose of this Fric test is the qualitative and semiquantitative diagnosis of symptomatic dermographism.
For the diagnosis of symptomatic dermographism, Fric test should be held perpendicular to the skin of the upper back or volar forearm for approximately 10 cm. Apply just enough pressure to have good contact with the skin so that all the pins are almost invisible [Figure 1]. Patients should be off antihistamines for wheal response. When all pins induce wheal response, the symptomatic dermographism can be judged as severe [Figure 2].
Figure 1.
Fric test instrument held on the skin
Figure 2.
Severe dermographism
References
- 1.Godse KV. Use of a ballpoint pen in the diagnosis of physical urticaria. Indian J Dermatol. 2011;56:119–20. doi: 10.4103/0019-5154.77576. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Wiwanitkit V. Ballpoint pen in the diagnosis of physical urticaria. Indian J Dermatol. 2012;58:134. doi: 10.4103/0019-5154.77576. [DOI] [PMC free article] [PubMed] [Google Scholar]
