INFECTIOUS SKULL BASE OSTEOMYELITIS-STILL A LIFE-THREATENING DISEASE

Abstract

To the Editor: We read with great interest the article by Drs. Djalilian, Shamloo, Thakkar, and Najme-Rahim titled "Treatment of culture-negative skull base osteomyelitis", presenting new treatment regimen of culture-negative skull base osteomyelitis which resulted in a high cure rate and a short (4 days) hospitalization period. All six patients, after 6 weeks of antibiotic therapy, were carried out of the authors' institution (1). Because acute osteomyelitis of the skull base develops mostly in patients initially treated for benign external otitis with poorly controlled diabetes, it would be interesting to learn about glycemia level in these patients. Aggressive and strict control of blood sugar level is imperative to enhance immune function and reverse acidosis. The authors did not present the staging of skull base osteomyelitis; thus, information given in the article show the absence of poor prognostic factors such as facial paralysis, multiple cranial neuropathy, or intracranial extension, which suggests stage II by Davis et al. (2). In these cases, applying of generally accepted treatment regimen is usually successful. Antibiotic therapy carried out of the authors' institution doubtlessly lead to reduced treatment costs, but what is questionable is the level of medical safety of the patient. In Poland, intravenous antibiotic therapy is possible only in hospital. Opinions on the value of topical antibacterial drops are inconsistent. Some authors state that the use of topical antibacterial drops is inadequate and changes the bacterial flora, altering future cultures should they be necessary in the face of resistant bacteria and the necessity of future bacterial flora assessment. Others promote this kind of therapy (3,4). In our patients, we apply topical antibacterial drops after receiving a final result of bacteriologic examination of the ear swab; at this moment, only steroid drops are given. There are several opinions concerning hyperbaric oxygen (HBO) therapy value in skull base osteomyelitis. This clinical entity is generally accepted by national hyperbaric societies, American Undersea and Hyperbaric Medical Society (UHMS) and European Committee for Hyperbaric Medicine (ECHM), as an indication for HBO therapy. Rationality of HBO treatment in this disease has been proven in experimental and clinical trials. The following changes, resulting from exposition to HBO, were observed: vasoconstriction and decreased edema of damaged tissues, proliferation of fibroblasts, activation of neoangiogenesis, increase of dependent antibacterial activity of leukocytes, improved activity of osteoblasts and osteoclasts, and increased antibacterial effectiveness of some antibiotics (5). In the Department of Otolaryngology, Medical University of Gdansk, in the years 1997 to 2003, there were eight patients treated for malignant otitis externa. In six patients, infection was caused by Pseudomonas aeruginosa; in one patient, infection was caused by Staphylococcus sp., and in another one, infection was caused by Aspergillus sp. In three patients, clinical Stage I was diagnosed; in four patients, Stage II was diagnosed, and in one patient, Stage III. Standard mixed pharmacotherapy, topical management, and adjuvant HBO therapy were applied. Complete recovery was achieved in seven patients; in one patient with osteomyelitis caused by Aspergillus sp., intracranial complications developed, and the patient died. In this case, only serologic test for antimycotic antibodies and subsequent bacteriologic investigations were allowed to diagnose otogenic skull base osteomyelitis caused by invasive fungal infection (Fig. 1). Application aggressive antibiotic and antimycotic therapy was ineffective, the patient died 54 days after admission to our department.FIG. 1: A 65-year-old man; insulin-dependent diabetes mellitus; palsy of VII, IX, X, and XII nerves. Axial computed tomographic scan demonstrating extensive destruction of the right pyramid.The given above case report shows that infectious osteomyelitis, despite revolutionary pharmacotherapy progress, still remains a life-threatening disease. So in these cases, especially when etiology is unknown, applying treatment outside the hospital may be risky for patients. In our opinion, the treatment regimen presented by the authors is indicated only in limited number of patients, who, in general, are in good condition, with a disease of bacterial etiology, with well-controlled glycemia, without advanced osteomyelitis, and with a disease not involving the cranial nerves. Each case of infectious osteomyelitis should be considered as an indication for adjuvant HBO therapy, especially in advanced clinical stages (II and III) or cases that failed in "typical" treatment. Waldemar Narozny, M.D. Jerzy Kuczkowski, M.D. Boguslaw Mikaszewski, M.D. Department of Otolaryngology Medical University of Gdansk Gdansk, Poland