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Abstract
Actinomycosis is a rare invasive bacterial disease that is characterised by granulomatous inflammation often mistaken as malignancy. Traditionally, this has been managed with prolonged courses of antibiotics with durations up to 6–12 months. Surgical intervention as an adjuvant treatment has been shown to reduce the length of antibiotic treatment significantly to 4 weeks. We report a case of cervicofacial actinomycosis in a 12-year-old girl who was adequately treated with an 11-day course of antibiotics without surgical intervention and shows no signs of recurrence at 6 months post-treatment.
- ear
- nose and throat/otolaryngology
- paediatrics
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Background
Actinomycosis, caused by Actinomyces spp, is a rare invasive bacterial disease that is characterised by granulomatous inflammation and formation of abscesses and sinus tracts which discharge sulfur granules. A study conducted in USA says that the incidence is rare and the suggesting rates of one per 300 000, compared with a study in Europe estimating an incidence of one per million.1 2 Clinical presentation varies depending on to which anatomical site the infection has spread. Cervicofacial actinomycosis is the most common site, accounting for 50%–70% of cases.3–5 Identification of the causative organism requires prolonged culture in anaerobic conditions on a chocolate blood agar or enriched medium; this can take up to 20 days before the culture growth becomes significant.6 With cultures remaining sterile in greater than 50% of cases, this condition poses a challenge to clinicians regarding initiating treatment with antibiotics, which is the gold standard of actinomycosis.7 Moreover, there is a significant variability in the duration of antibiotic treatment described in literature, with some studies suggesting up to 12 months of antibiotics.8 Moghimi et al suggests a shorter course of treatment, whereby intravenous antibiotics is used in combination with surgical intervention – in the form of incision and drainage +/ debridement of necrotic tissue, until clinical improvement is observed. Treatment was completed with a 2–4 weeks course of oral antibiotics.9
In this case report, we present a case of a 12-year-old girl with a cervical actinomycosis infection who only required an 11-day course of antibiotics, intravenous with oral switch, to achieve resolution of symptoms.
Case presentation
A previously fit and well 12-year-old Caucasian girl was presented with a 2-week history of a left sided neck lump. She had been presented to her general practitioner 5 days prior and was diagnosed with a reactive lymph node. However, a rapid increase in size with an associated new, adjacent erythematous swelling prompted further investigation. The mass was mildly tender and she had no upper aerodigestive tract symptoms. She was otherwise systemically well with no prodromal viral illness.
The mass measured approximately 8×4 cm and was firm, ‘craggy’ and irregular. It extended from below the angle of the mandible towards the midline. There was a swelling around the inferior aspect of the original lump that was fluctuant, erythematous and measured 2×1 cm.
Thorough oral examination yielded no abnormal findings. Dentition was noted to be good with no tooth decay or gingivitis present. She had no complaints of oral pains or symptoms suggestive of an oral infection.
Investigations
Blood specimen revealed a mildly raised white cell count of 11.4×109 /L and neutrophilia of 9.2×109 /L. The rest of her blood results were within the normal range. An ultrasound report noted irregular hypoechoic material in the lower left anterior neck which extended from the left of the midline, anterior to the lateral aspect of the left lobe of the thyroid, extending laterally behind the sternocleidomastoid muscle to its posterior border. There was a large deeper component and a small extension superficially forming the palpable 2 cm diameter lump which was 11 mm in depth but in continuity with the deeper abnormal tissue (figure 1). A few small pockets of fluid were noted. The inferior sternocleidomastoid was involved in the inflammatory mass. Appearances on the scan raised the possibility of a congenital branchial cyst with associated infection. No other cervical nodes of significance were noted. Further imaging was deemed unnecessary to avoid radiation exposure due to patient’s young age.
Ultrasound of left neck level IV demonstrating the large deeper component with a small extension superficially forming the palpable erythematous lump.
A fine needle aspiration was performed. Microbiology results at days 4 and 13 yielded no growth except for some white cells. Enrichment culture at day 20 isolated both Prevotella disiens and Actinomyces odontolyticus. The Prevotella disiens was sensitive to both co-amoxiclav and metronidazole. Further investigation revealed two different species of Actinomycoses, namely Actinomyces georgiae and Actinomyces naeslundii. Both strains of Actinomyces were sensitive to a wide range of antibiotics including co-amoxiclav and ceftriaxone.
Treatment
She was commenced on IV flucloxacillin on admission which was changed to IV ceftriaxone within 24 hours. After 4 days of treating with IV antibiotics, she was discharged to home with 250/62 mg co-amoxiclav three times daily for a week (note: this was all pending culture and sensitivity). A follow-up 4 days after discharge revealed that the lump was decreasing in size with the swelling spontaneously draining by itself.
Outcome and follow-up
At 5 weeks, the lump had reduced in size to a diameter of 2 cm with no residual fluctuance or discharge. Following a discussion between ear, nose and throat (ENT) and the paediatric infectious disease teams, a decision was made to opt for an active monitoring approach given the length of time off antibiotics with no relapse of symptoms. This approach was taken with caution and close follow-up given the previous, much more prolonged, antibiotic durations as described in the literature.
A follow-up at 15 weeks showed no recurrence of disease, a 1 cm area of erythema in the left level III/IV region of the neck, in keeping with the site of previous spontaneous discharge. Palpation of the rest of the neck was unremarkable. Follow-up ultrasound imaging demonstrated a small residual skin sinus in the left lower neck associated with short blind ending tract within the subcutaneous fat of 1.7 cm in length, extending medially from the skin abnormality, to a maximum depth of 5 mm (figure 2). At this point, she was discharged from the care of the team, with strict advice to contact the ENT team for a review on her symptoms change or return. At 6 months post-treatment she remained well with no recurrence of the disease.
Ultrasound of left neck level IV demonstrating small residual skin sinus associated with a short blind ending tract.
Discussion
Concomitant infections are commonly found in Actinomycosis, with polymicrobial infections occurring in 75%–95% of cases. This forms a synergistic effect, enhancing the infectious process of actinomycotic lesions.10 11 Coagulase-negative staphylococci (39.1%) are most commonly found concomitantly in cervical Actinomycosis, with Prevotella and Bacteroides spp also widely present as a co-infecting microbe (25.1%).
Typically, treatment of cervical actinomycosis is with an extended course of antibiotics, ranging anywhere from 6 to 12 months.12 However, emerging evidence demonstrates a significant reduction in length of treatment if an incision and drainage is performed as an adjunct. A case series from 2013 noted a mean duration of 4 weeks of antibiotic treatment after surgical incision, thus supporting the hypothesis of R. Nagler et al that compartmentalisation of the organisms in the sulfur granules and granulation tissue make antibiotic treatment ineffective without resection of the lesion.9 13 This case highlights that a short course of antibiotics is a valid therapeutic option for patients that have not undergone surgical intervention. An 11-day antibiotic course and a short admission meant that the possible side effects of the medication and risk of future antibiotic resistance were minimised. Furthermore, there is a significantly reduced psychological burden on the child who has been not taking daily medication for many months. However, it could be argued that as the swelling had self-discharged at day 4, the compartmentalisation of Actinomyces was disrupted thus increasing the efficacy of antibiotic treatment.
Another approach to the treatment of actinomycosis, as suggested by Eastridge et al, is for individualised length of antibiotic treatment, depending on the disease severity and response to treatment.14 Close surveillance of the disease with serial imaging should be considered to ensure complete resolution, with ultrasonography being the most useful and widely recommended modality for cervical actinomycosis.15 The patient in this case displayed dramatic improvement of symptoms with just 3 days of antibiotics, allowing us to discharge her with oral antibiotics and close follow-up. The ultrasound scan carried out at 15 weeks helped guide the decision to discharge her from the team’s care.
Although prognosis of actinomycosis is generally favourable, with high resolution rates, correct diagnosis of the disease remains paramount in optimising patient care. Previous studies have shown the failure of clinicians to diagnose actinomycosis, oftentimes mistaking the disease for a malignancy or an inflammatory condition.1 Perhaps this is due to the presentation of the condition, as a continuous and progressive spread of disease eventually forming a cold abscess. Frequently the findings on palpation may be similar to, and thus confused with, that of a malignancy. Although the cornerstones of diagnosis are bacterial cultures and pathology, positive results often take many weeks to become apparent, as demonstrated in this case and corroborated in the literature.5 It is essential to understand the different anatomical sites that actinomycosis may present and their correlating clinical features, in order to facilitate prompt diagnosis and instigation of treatment.3
Learning points
Actinomycosis remains difficult to diagnose clinically, with prolonged cultures required.
Clinicians should keep this differential diagnosis at the back of their mind when encountering rapidly growing masses that mimic inflammation or malignancy.
Cervicofacial actinomycosis can potentially be treated safely with a limited course of antibiotics without surgical intervention.
The authors recommend close patient monitoring during the first few months post-treatment if this approach is taken.
Ethics statements
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References
Footnotes
Contributors JY - designed, analysed and interpreted data. Drafted case report. MH - analysed and interpreted data. Revising draft critically. AI - final approval of the published version. Revising draft critically.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.