A 48-year-old man visited our department with bilateral, symmetric areas of alopecia, associated with a local burning sensation, on the external anterior surface of the thighs. (Fig. 1). Dermatoscopy showed no hair follicles, follicular orifices, or yellow, white, or red spots. We observed hypoesthesia to a light touch in the region of both lateral femoral cutaneous nerves. Neurography found no sensory evoked potential. On questioning, the patient reported that he wore very tight pants every day between the ages of 14 and 22 years. A diagnosis of bilateral meralgia paresthetica caused by tight pants was made.

Figure 1

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Meralgia paresthetica and diseases such as notalgia paresthetica and brachioradial pruritus are classed as neurocutaneous dysesthesias. Their etiology is highly varied and is divided into iatrogenic or spontaneous. These categories are in turn subdivided into idiopathic, metabolic, and mechanical (such as obesity, pregnancy, or tight clothes). The condition is due to entrapment of or damage to the lateral femoral cutaneous nerve. The paresthesia affects the upper anterolateral or lateral surface of the thigh and is characterized by a sensation of burning, cold, stabbing, mild pain, anesthesia, or hypoesthesia. It has also been associated with alopecia and it has been speculated that it may have a traumatic origin due to the patient massaging the paresthetic area or to the influence of the nervous system on the hair.