Hypertrichosis after surgery for cubital tunnel syndrome

Abstract

A 37-year-old male was seen for medial elbow pain and paresthesia on the medial side of his left forearm. He denied having any weakness or pain in the neck and the left shoulder. There was no antecedent trauma, and his medical history was unremarkable except for Graves’ disease and urolithiasis. The neurological examination disclosed a positive Tinel’s sign over the cubital tunnel, hypoesthesia in the forth and fifth fingers and mild weakness of the ulnar nerve innervated intrinsic hand muscles on the left upper extremity. There was no hypothenar or intrinsic muscle atrophy. Nerve conduction studies were consistent with entrapment of the left ulnar nerve at the level of the cubital tunnel (normal on the right side). Likewise, sonographic imaging revealed focal mild enlargement of the left ulnar nerve immediately proximal to the cubital tunnel. Initially, the patient was followed conservatively with a nonsteroidal antiinflammatory drug, a static elbow splint and physical therapy for 2 months. However, as the patient’s symptoms did not improve, he underwent surgery where decompression and anterior submuscular transposition of the left ulnar nerve were performed via medial approach to the cubital tunnel. Postoperatively, the patient used a long arm–forearm cast was for 3 weeks. Thereafter, he noticed increased hair growth on the distribution of the ulnar nerve over the left forearm and hand (Fig. 1). He was called for a control visit with a diagnosis of local hypertrichosis. Increased growth of hair on nonandrogen-dependent parts of the body is called hypertrichosis. It is generally classified based on the time of onset (congenital or acquired) and distribution (localized or generalized) [1]. The etiologies for acquired localized hypertrichosis include inflammation involving the skin, such as produced by infection, recent surgery, trauma, radiation, burns, insect bites, dermatologic disorders, and medication, scleroderma, vascular conditions, cast application, and reflex sympathetic dystrophy [2–4]. It has been reported that hypertrichosis might even ensue in reflex sympathetic dystrophy secondary to lumbar disk herniation [4]. In our case, although surgery and cast use seemed to be the two possible contributors, our patient was interesting since hypertrichosis was present not only in one area but along the ulnar nerve dermatome. Therefore, keeping in mind the fact that increased blood supply is one of the main underlying mechanisms of hypertrichosis, we believe that altered sympathetic innervations (provided by the ulnar nerve) after release surgery might have played role in our patient. Accordingly, presenting this rare clinical scenario of hypertrichosis after surgery for cubital tunnel syndrome, we imply that similar complaints may occur not only due to the neural injury itself but also during the period of neural recovery.