Pseudomonas laryngeal perichondritis: unexpected diagnosis

Abstract

A 57-year-old male chronic smoker with underlying diabetes mellitus presented with dysphonia associated with cough, dysphagia and reduced effort tolerance of 3 months’ duration. Videoendoscope finding revealed bilateral polypoidal and erythematous true and false vocal fold with small glottic airway. The patient was initially treated as having tuberculous laryngitis and started on antituberculous drug. However, no improvement was observed. CT of the neck showed erosion of thyroid cartilage, which points to laryngeal carcinoma as a differential diagnosis. However, the erosion was more diffuse and appeared systemic in origin. The diagnosis of laryngeal perichondritis was made when the histopathological examination revealed features of inflammation, and the tracheal aspirate isolated Pseudomonas aeruginosa. The patient made a good recovery following treatment with oral ciprofloxacin.

Background

Laryngeal perichondritis was once a frequent complication of systemic infection caused by typhoid fever.^{1 2} It has become less common nowadays due to the advancement of antibiotics usage in healthcare services.^{1 2} With the advent of antibiotics in the 1930s, primary infectious causes were significantly reduced, while other causes, for example, trauma (mechanical and iatrogenic), irradiation, tumours and foreign bodies, became relatively more common.^{1 2} Less common causes include measles, scarlet fever, tuberculosis (TB), gonorrhoea, syphilis, diphtheria, mycoses and carcinoma.

The present case demonstrated the diagnostic dilemma in view of the clinical presentation, endoscopic and radiological findings, overlapped with other possible diagnoses which mimic laryngeal carcinoma and laryngeal TB. A peculiar presentation of laryngeal perichondritis caused by Pseudomonas aeruginosa clinically mimicking laryngeal TB with suspicion of laryngeal carcinoma is discussed.

Case presentation

A 57-year-old man with underlying uncontrolled diabetes mellitus presented with 3 months of productive cough with blood-stained sputum associated with hoarseness and reduced effort tolerance. He also complained of frequent throat clearing and foreign body sensation in the throat. He had loss of appetite and weight loss of 15 kg in the past 3 months prior to presentation. The patient was a smoker with no family history of malignancy or contact with patients with tuberculosis (TB). He also had received complete bacille Calmette-Guérin vaccination. Clinically, there was hoarseness with overall dysphonia of grade 3 (GRBAS scale (G=Grade or overall severity of dysphonia, R=Roughness, B= Breathiness, A=Aesthenia, S=Strain)) with main component of roughness and soft inspiratory stridor. Videoendoscopy of the larynx (figure 1) showed generalised oedema involving the false and bilateral true vocal folds, as well as thick endolaryngeal mucous. The false vocal fold appeared bulky, obscuring the view of true vocal folds except the posterior part. Thus, the mobility of the vocal folds could not be elicited. The visualised posterior parts of the true vocal folds were inflamed, polypoidal and oedematous. Laryngeal stroboscopic examination revealed the absence of mucosal wave of the true vocal folds. Enhanced laryngeal imaging technology using i-scan (PENTAX Medical) showed the absence of a perpendicular pattern of intraepithelial papillary capillary loops that may indicate neoangiogenesis of cancerous tumour.

Figure 1.

Endoscopic view of the larynx at initial presentation. White arrows show the oedematous false vocal fold.

Investigations

Due to the suspicion of tuberculous laryngitis, tests to diagnose tuberculous infection were performed, which includes a chest radiograph, erythrocyte sedimentation rate, Mycobacterium tuberculosis complex PCR, M. tuberculosis complex DNA (Gene Xpert) and Ziehl-Neelsen staining of the patient’s sputum. The results showed a raised erythrocyte sedimentation rate of 90 mm/hour and positive Mantoux test, making tuberculous laryngitis highly likely. Due to a high index of suspicion, the patient was started on anti-TB. However, there was no improvement after 2 months of the anti-TB treatment. Thus, CT of the neck was performed, revealing a swollen area between the outer and inner perichondria, which shows homogeneous diffuse enhancement, with loss of ossification (figure 2). No evidence of fluid density accumulation or rim enhancing capsule of abscess detected within this oedematous region between inner and outer perichondria.

Figure 2.

Axial contrast-enhanced CT of the larynx in bone algorithm at the level of the arytenoid cartilages. CT of the neck shows diffuse erosion of thyroid cartilage. Fairly homogeneous diffuse enhancement, with loss of ossification shown by the arrows.

The patient subsequently underwent direct laryngoscopy and examination under anaesthesia, which revealed oedema of bilateral false vocal folds with the presence of polypoidal inflamed mass arising from bilateral ventricles, true vocal folds, anterior commissure and subglottic region with the presence of mucopus (figure 3). Histopathology examination results revealed chronic inflammation with no evidence of malignancy or granuloma. Tracheal aspirate culture and sensitivity revealed isolated P. aeruginosa with negative for M. tuberculosis culture and sensitivity.

Figure 3.

Endoscopic view of the larynx during endolaryngeal microsurgery on retracting the false vocal fold with laryngeal spreader. Polypoidal mass (black arrows) could be seen arising from the ventricles, true vocal fold and from underneath the vocal fold. The white arrow is the endotracheal tube.

Differential diagnosis

High suspicion of tuberculous laryngitis was based on the symptoms and signs, raised erythrocyte sedimentation rate and positive Mantoux test. However, there was no improvement after starting on anti-TB treatment. CT of the neck showed erosion of thyroid cartilage, and histopathological examination revealed features of inflammation and malignancy was ruled out. The diagnosis of laryngeal perichondritis was made based on the histopathological examination and the tracheal aspirate isolated P. aeruginosa.

Treatment

Following discussion with a respiratory physician, the patient was started on anti-TB at initial treatment. This was due to the bizarre appearance of the larynx and high index of suspicion of tuberculous laryngitis. However, the symptoms and signs did not show any improvement, despite 2 months of anti-TB treatment.

After further thorough investigations which included CT of the neck, histopathology examination, tracheal aspirate culture and sensitivity results, the patient was treated with oral quinolone for the treatment of Pseudomonas laryngeal perichondritis. The patient was prescribed with ciprofloxacin 500 mg two times per day for 8 weeks, and his signs and symptom began to improve 2 weeks after the initiation of treatment.

Outcome and follow-up

The patient’s signs and symptoms, together with the repeat endoscopic findings, showed tremendous improvement after 8 weeks of treatment with ciprofloxacin (figure 4A).

Figure 4.

Endoscopic view of the larynx (A) and a repeat CT image (B) after completion of ciprofloxacin at 8 weeks. (A) Larynx on iScan 3 (Pentax) with no signs of inflammation. (B) Repeat CT showed return of ossification (arrows) to the previously swollen and enhancing central aspect of the thyroid cartilage laminae.

A repeat CT was performed, approximately at the same axial slice, showing gradual return of ossification to the previously swollen and enhancing central aspect of the thyroid cartilage laminae (figure 4B).

Discussion

The present case is a rare presentation of an isolated case of laryngeal perichondritis due to P. aeruginosa infection in a previously healthy person. The patient had no history of irradiation to the neck, trauma or history suggestive of malignancy. He presented with chief complaints of chronic cough, dysphonia, dysphagia and reduced effort tolerance with underlying uncontrolled diabetes mellitus. Videoendoscopy of the larynx showed oedematous false vocal folds and polypoidal true vocal folds. These clinical presentations may resemble the presentation in patients with laryngeal TB.^{3 4}

TB of the otorhinolaryngeal region is uncommon but not a rare clinical problem. Primary laryngeal TB without coexisting pulmonary TB is possible.⁵ The presenting symptoms are typically hoarseness, odynophagia and dysphagia, along with loss of weight and loss of appetite.⁵ The appearance of the larynx may vary due to diffuse erythema, granulomatous or polypoidal changes or painful ulcerations,^{4 5} in which the vocal folds are the the most common site to be affected (50%–70%).³ A clinical diagnosis of laryngeal TB is challenging, as the symptoms may mimic infective or non-infective pathological conditions.⁵

In the present case, laryngeal TB was suspected initially instead of malignancy despite the presence of risk factors (male and chronic smoker) because of three reasons. First, Malaysia is an endemic area of TB. Second, the characteristics of inflamed polypoidal growth are not typical of malignant tumour on the larynx. Third, with the use of enhanced imaging technology of i-scan, we could not visualise any abnormal perpendicular submucosal vascular pattern that was commonly associated with malignant tumour. The commencement of anti-TB was also based on raised erythrocyte sedimentation rate, positive Mantoux test and high index of suspicion based on symptoms and signs. However, the treatment did not lead to relieving the symptoms, and endoscopic examination findings remained unchanged. Thus, a CT scan and biopsy were performed, which revealed swelling with loss of ossification of the thyroid cartilage, and histopathology examination showed evidence of inflammation. Tracheal aspirate culture and sensitivity isolated P. aeruginosa; hence, a diagnosis of laryngeal perichondritis was made.

Symptoms and signs of laryngeal perichondritis are non-specific. Documented symptoms in the literature include hoarseness, throat pain and dyspnoea in which the pain was aggravated by swallowing and talking. Indirect laryngoscopy may reveal oedematous, erythematous, granular mucosa with narrowed laryngeal lumen. Soft tissue oedema or cricoarytenoid joint inflammation may result in decreased vocal fold mobility.¹ Based on the literature, P. aeruginosa is the most common opportunistic organism associated with perichondritis.⁶ Infection caused by this organism begins with superficial colonisation of cutaneous or mucosal surface. Its high invasive capacity and virulence factor may progress to involve the underlying tissue.⁶ There was a reported case of Pseudomonas laryngeal perichondritis that progressed to laryngeal abscess in an immunosuppressed patient despite antibiotics.² Complications due to perichondritis may include aspiration pneumonia, mediastinitis and vocal fold fixation. The worst complication is the destruction of the cartilaginous framework with subsequent laryngeal stenosis.¹ Total laryngectomy may be the last option of treatment when perichondritis and necrosis have led to airway collapse.¹

A suspected laryngeal abnormality or laryngeal neoplasm can be further evaluated with CT or MRI to assess the deep submucosal structures and spaces.^{7 8} If granulomatous tissue does become visible on CT or MRI, it usually cannot be differentiated from neoplasia. However, diffuse laryngeal soft tissue lesions with the combination of pulmonary TB without destruction of the laryngeal architecture should raise the suspicion of laryngeal TB.⁸

The present patient was treated with oral ciprofloxacin for a duration of 8 weeks and his signs and symptom began to improve 2 weeks after the initiation of treatment. It was stated in the literature that antibiotic treatment should be initiated only if culture results are positive. A recent study reported that a 14-day course of antibiotic may be insufficient to treat chronic bacterial laryngitis. The shortest duration of antibiotic that was effectively used for P. aeruginosa laryngitis was 3 weeks. Intraepithelial bacteria may require prolonged antibiotic treatment.⁹ Monitoring of treatment progress was done by evaluating the trend of erythrocyte sedimentation rate, return of vocal fold mucosal waves on a laryngostroboscope, as well as improvement of inner cortex thyroid cartilage appearance and resolved supraglottic oedema on CT scan.

Patient’s perspective.

At the time when I first experienced hoarseness and sore throat, I thought it was just a normal sore throat. I went to seek treatment at several general practitioner clinics, but I was just prescribed with throat gargle and antireflux medications. I was an ex-smoker and I don’t have family history of cancer or tuberculosis infection. I had received complete bacille Calmette-Guérin vaccination. However, my symptoms get worst after a few months and it was accompanied by shortness of breath on exertion and reduced effort tolerance. I felt breathless whenever I performed normal daily activities and walked around within short distance. I need to strain to produce voice. My family and colleagues had slight difficulty communicating with me as they always heard me wrongly due to my hoarseness. My voice was not clear enough for them to understand and require repetitions. My job scope does not require me to use my voice excessively and at that point of time, I was still working like usual. I developed dysphagia and odynophagia, subsequently causing loss of appetite and loss of weight. I was then referred to a laryngology surgeon in Universiti Kebangsaan Malaysia 3 months later due to my unresolved problems. After a thorough investigations and due to high suspicion of tuberculous laryngitis, I was started on antituberculosis (TB) medication after discussion between the otorhinolarynoglogy team and the respiratory team. Honestly, I don’t feel better when I was started on anti-TB medication. A CT scan was performed and subsequently I was subjected for an operation to take a biopsy from my throat as the CT showed extensive disease. However, the result from the specimen taken was negative for TB and cancer. I was diagnosed with infection of the throat and was treated based on the culture and was started on ciprofloxacin. After 8 weeks of treatment, I felt different! Hoarseness improved and I could breathe better. I can eat like normal, taking solid foods. I shall say that the symptoms improved by 80%. I feel much better now and am able to speak clearer. Occasionally, however, I still have intermittent mild breathlessness on exertion in which I was informed in advance regarding the possibility. I am currently back to working at the telecommunication company and resumed my routines.

Learning points.

• This is a peculiar presentation of laryngeal perichondritis caused by Pseudomonas aeruginosa clinically mimicking laryngeal tuberculosis (TB) with suspicion of laryngeal carcinoma.

• Laryngeal perichondritis is a differential diagnosis of an immunosuppressed patient who presents with inflamed and oedematous larynx with diffuse erosion of the inner cortex of the thyroid cartilage.

• A specimen for culture and sensitivity should be considered when there is a suspicion of infection.

• High index of suspicion of such diagnosis is especially appropriate when a lack of improvement with anti-TB treatment is observed.