[A rare side effect of mesotherapy: Nicolau syndrome]. / Un effet indésirable rare de la mésothérapie : la dermite de Nicolau.

BACKGROUND: Nicolau's livedoid dermatitis is associated with drug-induced embolism in the cutaneous arterial bed, generally as a result of accidental intra-arterial injection. Herein, we report a case that is somewhat surprising because of its late onset following mesotherapy injections. CASE REPORT: A 53-year-old man, with a history solely of tendinopathy for which he underwent mesotherapy sessions, consulted for livedoid lesions of the front of the knee with central necrosis. History-taking revealed a final course of mesotherapy three weeks earlier for patellar tendinitis below the left kneecap; intradermal injection of procaine and piroxicam had been unusually and intensely painful. The remainder of the clinical examination revealed additional livedoid lesions on the outside of the left ankle as well as purpuric lesions on the pads of the toes on the left foot. Laboratory tests revealed nothing of note. Skin biopsies of the livedoid circumference of the lesion showed arteriolar emboli of an amorphous material within the dermis obliterating the arteriolar lumen. The clinical appearance of skin lesions after mesotherapy led us to a diagnosis of Nicolau livedoid dermatitis. DISCUSSION: Nicolau dermatitis is a rare skin complication described as occurring mainly as a result of intramuscular injections. The reported case is special because it comprises Nicolau dermatitis arising out of a session of mesotherapy employing an intradermal injection. However, there are only very few cases in which subcutaneous injections have induced Nicolau dermatitis. The pathophysiology is not well known, but several mechanisms are involved: arterial ischaemia by vasospasm or thrombosis. In this case, the semiotic appearance of the lesions and histological analysis militate in favour of accidental injection of a skin product into an arteriole, resulting in obliteration of the latter. Mesotherapy can induce Nicolau dermatitis.

[Two cases of cutaneous erythema following spinal cord stimulation]. / Erythème cutané provoqué par une neurostimulation cordonale postérieure: deux observations.

INTRODUCTION: Cutaneous complications following implantation of an electric system have been reported mainly after the implantation of pacemakers, cardiac defibrillators and morphine pumps. However, cutaneous complications following implantation of spinal cord stimulators are rarely described in the literature. Here we report two cases of cutaneous eruption at the spinal cord stimulation site, one involving foreign-body reaction to silicone in the neurostimulator electrodes or connector block and the other comprising contact dermatitis to silicone. CASE REPORTS: Case 1: A 43-year-old woman had been implanted with a spinal cord stimulator. Four months after implantation, burning sensation and cutaneous inflammatory erythema were observed in the dorsolumbar region, with reduced efficiency of stimulation. Removal of the neurostimulator led to resolution of the cutaneous symptoms. Histopathological examination of the biopsy sample showed foreign-body granuloma formation. The same symptoms subsequently recurred on the surgical scar and histopathology showed granuloma formation in response to particles of silicone present in the connector. The cutaneous eruption subsided rapidly after excision. Case 2: In a 60-year-old man implanted with a spinal cord stimulator, pruriginous reticular erythema was rapidly observed on the skin just above the neurostimulator, with papules around the erythema. Histopathology of two cutaneous biopsies showed evidence of contact dermatitis. Skin-patch tests performed with components of the neurostimulator leads proved positive to two types of silicone after 72 hours. The eruption was successfully controlled using topical corticosteroid therapy. DISCUSSION: Reports of cutaneous eruptions after spinal cord stimulation are extremely rare. Here we report two different cutaneous reactions with two different pathophysiological mechanisms, both involving silicone. The first case is original because it is the first documented case of a foreign-body reaction involving granuloma formation in response to particles of silicone present in the components of a neurostimulator. The second case concerns contact dermatitis to silicone (present in the connector block and electrode sheaths).