Periodontitis caused by Actinomyces spp. in a child with Ascaris lumbricoides and Trichocephalus trichiurus: a case report

Actinomyces spp. is a gram-positive facultative anaerobic bacteria, normal to the oral cavity endogenous flora. Infections caused by Actinomyces spp., especially cervicofacial actinomycosis, are rare in children. This article aims to present a case of periodontitis caused by Actinomyces spp. in a 03 years old multi-parasitized child, and to discuss the eosinophilia interaction and the immune response to the parasites.


INTRODUCTION
Actinomyces spp. is a gram-positive facultative anaerobic bacteria, normal to the oral cavity endogenous flora 1 . Current literature describes 47 species², and Actinomyces israelii is among the most prevalent ones¹ and can be found in mucous membranes, mainly in the oral cavity, colon and urogenital tract³ ,4 . Infections caused by Actinomyces spp., especially cervicofacial actinomycosis, are rare in children but they can affect any age, most frequently affecting girls in association with fever and pain 5 .
Actinomyces spp. strains are predominant in periodontal tissue, both in physiological and inflammatory conditions 6 . Bacteria is usually established in stones, periodontal pockets, carious lesions, teeth and oral mucous membrane 7 .
Diagnosis is given by the histopathological confirmation of sulfur granules, positive culture and/or isolation of the Actinomyces spp. species 5 . Periodontal lesions caused by infections by such agent are ideally treated with penicillin.
This article aims to present a case of periodontitis caused by Actinomyces sp. in a 3 years old multi-parasitized child, and to discuss the eosinophilia interaction and the immune response to the parasites.

CASE REPORT
A 3 years of age female child, born and living in the Northeast of Brazil, was admitted with ulcerative periodontal lesion in the upper gum ( Figure 1), purulent, associated with claim of fever for two weeks.
Upon physical examination, patient presented a good general state, mild paleness, three centimeters hepatomegaly below the right costal margin and no skin or mucous membranes bleed. During hospitalization, the patient was submitted to a biopsy for culture of lesion.
Lab tests results were hemoglobin equal to 11.6 mg/dL; hematocrit equal to 36%; leukocyte count of 14,700/mm³ (25% of eosinophils, 35% of lymphocytes and 35% of segmenters); platelet count of 270,000/mm³; C-reactive protein lower than six; serum iron of 63 mcg/dL and stool test showed Ascaris lumbricoides, Giardia lamblia, Endolimax nana and Trichocephalus trichiurus. A skull CT scan was also performed and showed aspects of sinusitis, concha bullosa, deviated nasal septum and adenoid vegetation ( Figure 2). Therapy was started with 8 ml of Albedanzole 40 mg/mL for five days, three days being administered at the hospital and the remaining at home.   Thirteen days after hospital discharge, the biopsy showed bone tissue permeated with filamentous bacteria colonies that suggested Actinomyces ssp and polymorphonuclears (Figure 3). At that time, the patient was readmitted with two centimeters ulcerative lesions in both sides of upper gum, purulent discharge, without dental involvement, daily fever, pain after eating and enlargement of submandibular, anterior cervical and occipital lymph nodes, all with a fibroelastic appearance.
Treatment with a 5,000,000 UI dosage of intravenous Crystalline Penicillin every six hours was started. New lab tests were performed and their results were: hematocrit equal to 34.2%; leukocyte count of 18,200/mm³ (24% of eosinophils, 50% of lymphocytes, and 22% of segmenters; platelet count of 222,000/mm³; C-reactive protein lower than six; GOT: 41U/L; GPT: 12 U/L; sodium of 130 mEq/L and potassium of 4.5m Eq/L.
Patient clinical features improved with fever reducing since the beginning of therapy and ulceration regression. Treatment plan is thirty days of crystalline penicillin followed by, at least, five months of amoxicillin.

DISCUSSION
The case presented sparks scientific interest as it introduces localized shapes of lesions by Actinomyces spp. in gingival region, which are extremely rare. In addition, the patient has no history of previous dental manipulation, traumatic lesions of oral mucosa, use of chlorhexidine gluconate oral rinse 0.12% nor poor oral hygiene that could justify the tissue destruction that caused the infection. The absence of such clinical features hampered the initial clinical suspicion and, therefore, the early diagnosis.
One of the things that caught the authors' attention in this case was the presence of intestinal parasitism by Ascaris lumbricoides and Trichocephalus trichiurus and 25% of eosinophils. Eosinophilia has several causes. In developed countries it usually occurs by eosinophilic enteropathy and allergic immune disorder, however, in tropical countries and underdeveloped regions, one of the main causes is intestinal parasitism.
There is, in fact, the possibility that the immune response deviation to Th-2 might have predisposed the Actinomyces spp. multiplication and dissemination, since Th-2 response stimulates IgE production and eosinophils and mastocytes activity, for combating against extracellular bacteria and helminths 13 . Thus, IgE would be blocking neutrophils action, benefiting pathological reactions by Actinomyces spp. Unfortunately, it was not possible to measure IgE levels in the reported case.
Although Th-1 and Th-2 responses act in a balanced way, seeking for immune homeostasis, it is well known that an immune response deviated to Th-2, in infections caused by intracellular agents, is adverse to the host 14 since it increases susceptibility to infections and these organisms' proliferation and dissemination.
Regarding the intestinal parasitism caused by Ascaris lumbricoides and Trichocephalus trichiurus, infections caused by such helminths -together with several environment changes, such as coinfections, climate, diet and comorbidities and with polymorphism of the immune response to the host genes -can worsen or improve allergies and autoimmunity [15][16][17] .
In addition, immune response to helminths is usually controlled by Th-2 together with an extended compartment of regulatory T cells (Treg), that modulates and dampens inflammation -creating a harsh environment to helminths while restoring the damages caused by the parasites, as opposed to type 1 inflammatory response which is oriented to bacteria and viruses microorganisms [18][19][20][21] . As Tregs play a dual role in infections by helminths, protecting the host from excessive inflammatory response to the infection or reducing protective immunity; it allows for infections to become chronic [22][23][24][25] .
Therefore, the authors believe that another condition that could explain the described periodontitis is the helminthiasis occurrence, since it would reduce the protective immunity provided by the Tregs and, thus, triggering the infection.
Child recovery at the end of the treatment was certainly due to the use of Penicillin. In addition, it is possible that the albedanzole therapy eliminated parasites and modified the inflammatory response.
Finally, we conclude that this intestinal parasitism was the main factor behind the actinomycosis' severity.