**2. Urticaria factitia (dermatographism)**

Urticaria factitia (UF) is also known as dermographic urticaria and symptomatic dermatog‐ raphism. UF is the most common type of physical urticaria (PU) [1]. It must be differenti‐ ated from simple dermatographism in which whealing without itching is seen after moderate stroking of the skin [2]. White dermatographism which is seen in atopic patients is not related

to UF [3]. UF is commonly seen in young adults and the mean duration of the disease was reported 3–9 years in different studies. The etiology of UF is still unknown [4]. Infections (hepatitis, upper respiratory tract infections), medications (progesterone, statins), and diabe‐ tes mellitus have been accused, but still, there is less evidence [5]. The pathogenic mechanism is believed to be the release of histamine following a mechano‐immunological trigger [6].

In UF, itchy, white/pink/red wheals are observed after friction, scratching, rubbing, or tight clothing. Wheals appear in a few minutes following the trigger and may last a few hours. UF should come to mind in such cases, and the diagnosis should be made after positive skin provocation test [7].

The provocation in UF can be done by scratching or rubbing the skin with a blunt object (e.g., closed ballpoint pen tip or wooden tongue depressor). The flexor aspect of the forearm is the most suitable site for the provocation. Five to ten minutes of waiting time is mostly enough to conclude [8]. Recent guidelines suggest threshold testing with more advanced devices called the dermographometer. With this device, predefined and reproducible pressures can be applied to the testing area. The minimal force which is necessary to induce whealing can be determined with dermographometer and the disease activity in time (i.e., the patient's response to therapy) can be easily monitored. A positive response is noted when the patient shows a wheal response and complain pruritus [9].

Treatment of UF is mostly symptomatic. Avoidance is the best strategy. It is possible to prevent or minimize whealing by some precautions. Decreasing mechanical irritation in daily life is the essential of the therapy [10]. For symptomatic cases, new generation, nonsedating antihis‐ tamines are suggested as first‐line treatment. In case of failure, the dose can be increased to fourfold. Type of the antihistamine can be changed, leukotriene antagonists and/or H2 anti‐ histamines can be added [11]. Next two drugs in the treatment course are cyclosporine A and omalizumab [10, 12].
