Psoriasis vulgaris is a chronic inflammatory skin disease with keratinous erythema as the main feature. The worldwide prevalence is 0.09–11.4% [4, 5]. The value has a very wide range because there are differences in prevalence depending on the region. It is less common in Asia and Africa and more common in Europe and the USA. For example, the prevalence rate in Japan was reported to be 0.34% . Although the etiology has not been fully clarified, it is thought that genetic predisposition, environmental factors, and autoimmune mechanisms are involved. In addition to skin symptoms, various conditions such as arthritis, cardiovascular disease, metabolic syndrome, inflammatory bowel disease, and depression can be complicated . For example, psoriasis is an independent risk factor for ischemic heart disease . Recently, an association of psoriasis vulgaris with abdominal aortic aneurysm and aortic stenosis was reported, and its pathophysiology is thought to be an inflammatory mechanism similar to that for atherosclerotic lesions . Therefore, we should consider that psoriasis vulgaris is not just a skin disease but a systemic inflammatory disease that can cause various complications. Conventional therapies for treatment of psoriasis include topical therapy, phototherapy, and systemic therapy. Systemic drugs include methotrexate, ciclosporin, and glucocorticosteroids. In the past decade, several biologics have been developed and approved.
PsA is an arthritis associated with psoriasis that occurs in about 1.3–34.7% of patients with psoriasis vulgaris [9, 10]. PsA affects a small number of joints asymmetrically, and the distal interphalangeal joint, knee joint, and spine are common sites. Common symptoms are stiffness, pain, swelling, and tenderness of the joints. It may have clinical symptoms similar to those of rheumatoid arthritis, but as in this case, more than 90% of the cases are negative for rheumatoid factor. The CASPAR criteria presented by Taylor in 2006 are often used for diagnosis .
PsA of the TMJ, which was a problem in this case, is exceedingly rare and only about 40 cases have been reported. Erosion, bony proliferation, bone surface flattening, and sclerosis are typical changes, and conventional radiography and a computed tomography scan are the most widely used methods for diagnosing PsA of the TMJ . Our patient decided by himself to discontinue treatment, and arthritis was not diagnosed or treated until hospitalization. Therefore, temporomandibular arthritis may have progressed. In our case, arthritis was diagnosed by an orthopedist for knee pain, but the TMJ and cervical movement were not evaluated before the operation. There has been no report from an anesthesiology department that psoriasis caused a difficult airway, and we did not recognize it in the preoperative period.
Airway problems during induction of anesthesia can lead to death, and careful preoperative evaluation and anesthesia planning are therefore important. In this case, several difficult airway predictors were recognized preoperatively. According to previous studies, Mallampati III, jaw protrusion-limited, male sex, presence of teeth, limited neck extension, and limited thyromental distance were shown to be predictors of a difficult airway. The probability of difficult mask ventilation was estimated to be 2.7% , and that of difficult mask ventilation combined with difficult laryngoscopy was estimated to be 1.69% . Therefore, we prepared video laryngoscopes such as AWS and a bronchoscope. However, even after administration of rocuronium, the mouth opening disorder did not improve, and it was impossible to insert the AWS intlock blade up to the glottis. Moreover, mobility of his TMJ did not change and it was difficult to raise the mandibular elevation. The risk of CICV increases when repeated intubations are attempted multiple times or with multiple devices . In this case as well, gradually mask ventilation became more difficult, and there was concern about upper airway and glottal edema due to multiple airway management operations. Therefore, according to guidelines for airway management , CICV was avoided by antagonizing the neuromuscular block, restoring consciousness, restoring patency of the airway, and resuming spontaneous respiration. The reason for the finally successful nasal intubation was that it is easier to maintain the bronchoscope in midline compared to that in the case of oral intubation, and the upper airway muscle tone is maintained after awakening. Thus, awake intubation via the nasal cavity using a bronchoscope may be a useful procedure for airway maintenance in patients with temporomandibular arthritis.
We experienced a case of difficult airway management of the patient who had range of motion of the limited TMJ and cervical extension caused by psoriatic arthritis. Although psoriasis vulgaris is very rarely associated with temporomandibular arthritis, anesthesiologists should consider that it can cause perioperative difficult airways.