[Livedo-like cutaneous sarcoidosis]

The cutaneous signs of sarcoidosis are extremely polymorphous and may be classified under several different headings.

Herein, we report the case of a 51-year-old female patient presenting bilateral livedo of the knees accompanied by systemic signs with polyarthralgia, impaired general state of health, weight loss, and a sensation of dyspnoea. Skin biopsy revealed giant-cell granuloma around the dermal vessels, with no caseous necrosis. Histopathological examination of the patient's blood vessels revealed no abnormalities. Laboratory tests showed high levels of angiotensin converting enzyme (1.5×ULN), bilateral mediastinal adenomegaly and incipient pulmonary fibrosis. Systemic sarcoidosis was diagnosed on the basis of the overall clinical and laboratory picture. The patient subsequently presented hepatic involvement and hypercalcaemia associated with the sarcoidosis; systemic corticosteroid therapy (prednisone) was initiated, with slow dose-reduction. The outcome was favourable with a return to normal laboratory values, regression of the adenomegaly and subsidence of the livedo.

The literature contains reports of a number of cases of livedo heralding sarcoidosis. The majority of such cases involved young or middle-aged female patients of Asian origin presenting systemic sarcoidosis, with a high frequency of ocular and neural involvement. Livedo could be accounted for by the specific disposition of granulomas around the arterioles, resulting in disturbance of local blood flow, which was probably associated with the mechanical compression of vessels and with the micro-thrombi noted at histology.

Livedo may be considered a clinical sign of cutaneous sarcoidosis. Laboratory tests to screen for sarcoidosis may be proposed in the exploration of atypical livedo.