Three Cases of Cutaneous Sarcoidosis: Search for Bacterial Agent by the 16S RNA Gene Analysis and Treatment with Antibiotics

Abstract

Background: The aetiology of sarcoidosis remains controversial. An infectious origin is often discussed, but only anti-inflammatory or immunosuppressive treatment is recommended. Objectives: To investigate the hypothesis of bacterial origin by treating cutaneous sarcoidosis with antibiotics. Methods: Patients with chronic cutaneous sarcoidosis, unresponsive to the usual treatment and not requiring systemic corticotherapy, were given combined antibiotherapy for 6 months. Search for bacterial DNA by amplification and sequencing of the 16S ribosomal RNA gene in skin biopsies of lesions before and after antibiotherapy was done. Results: Three patients received a combined treatment with clarithromycin 1 g/day and ciprofloxacin 1 g/day. No clinical changes occurred in 2 cases and transient worsening in 1. Amplification for bacterial DNA was positive in all skin biopsies. The sequencing of this DNA could not identify a unique bacterial species. Conclusion: No evident bacterial origin could be demonstrated; however, this approach should be extended to more patients.

Lupus miliaris disseminatus faciei: A Distinctive Rosacea-Like Syndrome and Not a Granulomatous Form of Rosacea

“…Up to 60% of patients with sarcoidosis experience spontaneous resolution, and an additional 10–20% of patients show resolution of lesions with the use of systemic steroids [15]. Treatment with antibiotics is subject to controversy, especially since no evident bacterial origin could be demonstrated [16]. …”

The granulomatous reaction pattern

“…107,108 Other cases do not appear to be related to systemic sarcoidosis and may be a sarcoidal reaction to a foreign body. 126,127 The main candidate is a cell-wall-deficient form of an acid-fast bacillus, similar, if not identical to, Mycobacterium tuberculosis. The association in many of these conditions is probably fortuitous.…”

Host-microbe interactions in the pathogenesis and clinical course of sarcoidosis

“…In addition, it is important to consider that sarcoid granulomas constitute a chronic inflammation, rather than an acute inflammatory response and thus, even if microorganisms are the triggering factor, antibiotics could be ineffective due to the absence of an active infection within granulomas. Indeed, some studies have reported no clinical response in sarcoidosis patients treated with antibiotics [149].…”