Treatment of Meralgia paraesthetica with Topical Capsaicin

Lluis Puig, Department of Dermatology, Hospital de la Santa Creu i Sant Pau, Avda. San Antonio M. Claret 167, E-08025 Barcelona (Spain) Meralgia paraesthetica is an uncommon neurologic disorder usually caused by compression of the lateral femoral cutaneous nerve. This nerve leaves the pelvic cavity at the anterosuperior iliac spine below the inguinal ligament and superficial to the sar-torius muscle. In its course it is vulnerable to entrapment, generally related with obesity, pregnancy or unknown causes [1]. Meralgia paraesthetica has also been described to appear as a result of neuromas [2], malignant tumours of the psoas muscle [3], metastatic carcinomas in the second lumbar vertebra [4] or following coronary bypass surgery [5], due to compression arising from prolonged supine position on the operating table. Meralgia paraesthetica is clinically characterized by a disturbed sensation at the an-terolateral side of the thigh. Patients can complain of pain, numbness, itching ordysaesthe-sia, and the perception of pinprick and touch is often diminished or lost. In some cases they Lluís Puig Department of Dermatology Hospital de la Santa Creu i Sant Pau Avda. San Antonio M. Claret 167 E-08025 Barcelona (Spain) refer a burning pain that can be unbearable. The femoral cutaneous nerve is only sensitive so the motor function remains uninvolved and the reflexes are normal. Electrophysio-logic tests and somatosensory evoked potentials can be useful as diagnostic procedures [6]. Many treatments have been advocated for meralgia paraesthetica [2]. Analgesia can be provided by nerve block or local infiltrations. Surgical procedures include neurolysis, transposition or decompression of the nerve and mobilization of the supra-inguinal ligament. The possible efficacy of topical capsaicin in the treatment of meralgia paraesthetica has not been previously reported, to our knowledge. A 54-year-old man was referred for evaluation of dysaesthesia in the anterolat-eral right thigh. His medical history included partial epileptic crisis due to a congenital arachnoid cyst in the left parietotemporo-occipital area which had been treated with carbamazepine for the last 3 years. He also suffered from aquagenic pruritus which was well controlled with the administration of hydroxyzine before showers. He complained of paraesthesias, numbness, itching and burning sensations localized on the anterolateral aspect of the right thigh of 2 months’ evolution. Physical examination did not reveal any cutaneous abnormality, and the results of complete blood cell counts and biochemical parameters were normal. The sensory response of both femorocutaneous nerves could not be evocated on electrophys-iological examination. The patient was instructed to apply topical 0.025% capsaicin cream five times daily on the lateral aspect of