Ulcerous skin lesions in Carpal Tunnel Syndrome

ARTICLE

Auteur(s) : Joaquín SOLA-ORTIGOSA 38725jso@comb.cat, Elisabet DILMÉ-CARRERAS, Maribel IGLESIAS-SANCO, Gemma MÁRQUEZ-BALBÁS, Manuel SÁNCHEZ-REGAÑA, Pau UMBERT-MILLET

Service of Dermatology, Hospital Universitari Sagrat Cor, C/París 83-85, E-08029 Barcelona, Spain

Carpal tunnel syndrome (CTS) is the leading cause of acroparaesthesia in upper limbs and the most common entrapment neuropathy [1-4]. Clinically, CTS is characterised by the insidious onset of neurological manifestations, predominantly at night, with tingling and numbness in the area of the thumb, forefinger and middle finger. As the condition progresses, it becomes difficult to grasp or to clench the fist, with pain in the hand that may spread to the elbow, with atrophy of the thenar muscles and reduced pain in advanced stages.

We report four cases of CTS diagnosed in our dermatology clinic, in which the clinical features were predominantly of a cutaneous rather than neurological nature, all with skin ulcerations on the forefinger, and acro-osteolysis in one case. The first patient was an 87-year-old woman with a 2-month history of a painless, non-suppurative, ulcerated, acral lesion on the tip of her left forefinger (figure 1). The second patient was a 73-year-old man with 5-month history of a small non-suppurative ulcer on the distal phalanx of the left forefinger, numbness of the thumb and forefinger. The third patient was a 79-year-old man with an 8-month history of a painful ulcer, with necrotic eschar on the surface, located on the distal left forefinger. He reported nocturnal paraesthesia with numbness of the left hand and hypaesthesia of the first three digits. Radiography demonstrated acro-osteolysis of the fingertip. The fourth patient was an 83-year-old woman with a 6-month history of difficulty in sewing and a 2-month history of a non painful ulcer on the tip of her right forefinger. Thumb opposition and grip were weak in her right hand with numbness of the thumb, forefinger and middle finger.

All four patients described here might represent cases of idiopathic origin, as no history of trauma or evidence of other systemic or local diseases were detected. Suspected CTS was confirmed by electroneurography, which demonstrated severe axonal degeneration of the median nerve and severely diminished conduction. The patients were referred to the traumatology department, where they underwent decompression of the median nerve followed by rehabilitation treatment. At subsequent check-ups ulcers are in resolution or are easier to manage and occur less often.

Skin lesions in connection with CTS are uncommon and are seen in severe cases with a long history, in which the fibres of the median nerve are severely damaged. There are few references to this condition in the dermatological literature, although subtle skin lesions are described in up to 20% of cases of CTS [3-5]. The most typical findings in advanced CTS are erythema and oedema of the fingers, bullous lesions or small foci of necrosis, acral vasomotor abnormalities (anhidrosis, swelling, Raynaud's phenomenon), sclerodermiform changes, nail dystrophy and mutilations. Distal necrotic lesions are probably caused by poor vasa nervorum function in the distal arterial vascularisation. Impaired thermalgesic sensitivity, and exposure to mechanical and thermal microtrauma may contribute to the onset of the lesions [3]. Surgical decompression of the median nerve improved symptoms in 60% of cases reported in the literature [3]. At this stage, the aim of treatment is to cure the blisters and ulcerations, or reduce the frequency at which they occur, and resolve the secondary problems of infections and acro-osteolysis [6].

Dermatologists should be alert to this syndrome, which features little in most dermatology textbooks. It should always be suspected in patients with ulcerous or necrotic lesions on the tips of the thumb, forefinger or middle finger. This syndrome is easily diagnosed if the possibility is not overlooked, and the prognosis of the lesions depends on early diagnosis and prompt treatment.

Disclosure

Financial support: none. Conflict of interest: none.

References

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2 M Bouvier, E Lejeune, M Rouillat, J. Marionnet Les formes ulcéro-mutilantes du syndrome du canal carpien Rev Rhum Mal Osteoartic 1979; 46: 169-176.

3 J Romaní, L Puig, G de Miguel, J.M. de Moragas Carpal tunnel syndrome presenting as sclerodactyilia, nail dystrophy and ACRO-osteolysis in a 60-year-old woman Dermatology 1997; 195: 159-161.

4 TM Fritz, G Burg, R. Böni Carpal tunnel syndrome with ulcerous skin lesions Dermatology 2000; 201: 165-167.

5 NH Cox, DM Large, WD Paterson, F.A. Ive Blisters, ulceration and autonomic neuropathy in carpal tunnel syndrome Br J Dermatol 1992; 126: 611-613.

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