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Background: Alkaptonuria (AKU) is a rare autosomal recessive disease characterized by a deficiency in an enzyme involved in the tyrosine and phenylalanine degradation. Patients suffering from this disorder develop a black coloration of cartilages known as ochronosis, leading to debilitating cartilage and arthritis at early ages. The spine is commonly involved but reports of lumbar disc disease are rare. Methods: We present a case of a lumbar disc herniation secondary to ochronosis, and we also provide a comparative analysis with other cases documented in the literature. For the literature search we selected manuscripts published in PubMed, Embase, Scopus, Ovid, and Science Direct between 1963 and 2022. Results: The mean age of the 25 included patients was 44.2 years (range: 22–69), and most of them were males (n = 19). The most common presentations were back pain and leg pain (n = 10), followed by lumbar radiculopathy (n = 9). Cauda equina syndrome (n = 2), thoracic myelopathy (n = 2), and cervical radiculopathy (n = 1) were less frequently observed. The lumbar region was the most affected area, with L4-L5 being the most affected level (n = 7), followed by L5-S1 (n = 4). Conclusion: AKU can lead to ochronotic spondyloarthropathy and, rarely, disc herniation, particularly in the lower lumbar region. Surgeons should note that black cartilage during a discectomy indicates likely ochronotic disc involvement. Diagnosis requires histopathologic and biochemical analyses of blood and urine, usually done retrospectively. Genetic confirmation is crucial due to the multisystem nature of alkaptonuria. Our case contributes to the literature on this rare condition, emphasizing the need for comprehensive diagnostics.

Ribhi Shawar1, Nicole Scangarella-Oman1, MaryBeth Dalessandro2, John Breton2, Monique Twynholm3, Gang Li4, Harmony Garges51Infectious Disease Center for Excellence in Drug Discovery, GlaxoSmithKline, Collegeville, PA, USA; 2Anti-infectives Medicine Development Center, GlaxoSmithKline, Collegeville, PA, USA; 3Infectious Diseases Medicine Development Centre Europe, GlaxoSmithKline, Greenford, Middlesex, UK; 4MDC BDS – Infectious Disease, GlaxoSmithKline, Collegeville, PA, USA; 5Anti-infectives Medicine Development Center, GlaxoSmithKline, Research Triangle Park, NC, USAAbstract: Retapamulin is a novel semisynthetic pleuromutilin antibiotic specifically designed for use as a topical agent. The unique mode of action by which retapamulin selectively inhibits bacterial protein synthesis differentiates it from other nonpleuromutilin antibacterial agents that target the ribosome or ribosomal factors, minimizing the potential for target-specific cross-resistance with other antibacterial classes in current use. In vitro studies show that retapamulin has high potency against the Gram-positive bacteria (Staphylococcus aureus, Streptococcus pyogenes, and coagulase-negative staphylococci) commonly found in skin and skin-structure infections (SSSIs), including S. aureus strains with resistance to agents such as macrolides, fusidic acid, or mupirocin, and other less common organisms associated with SSSIs, anaerobes, and common respiratory tract pathogens. Clinical studies have shown that twice-daily topical retapamulin for 5 days is comparable to 10 days of oral cephalexin in the treatment of secondarily infected traumatic lesions. A 1% concentration of retapamulin ointment has been approved for clinical use as an easily applied treatment with a short, convenient dosing regimen for impetigo. Given the novel mode of action, low potential for cross-resistance with established antibacterial agents, and high in vitro potency against many bacterial pathogens commonly recovered from SSSIs, retapamulin is a valuable enhancement over existing therapeutic options.Keywords: retapamulin, traumatic skin lesions, topical antibiotic, skin infections, Staphylococcus aureus