The orbital septum divides the preseptal space (soft tissues of the eyelid) from the orbital space (postseptal space) so that periorbital or preseptal cellulitis involve only the lids and not the orbit, whereas orbital or postseptal cellulitis is much more uncommon and involves the soft tissues of the bony orbit. An opthalmological examination is mandatory in assessing proptosis, chemosis, opthalmoplegia or decreased visual acuity as these findings highlight the presence of postseptal orbital cellulitis. However, the distinction beteween preseptal cellulitis and orbital involvement cannot be made with clinical examination alone and delay in treatment can result in blindness in up to 10% of patients . Orbital cellulitis is a serious infection in children and can result in significant complications as blindness, cavernous sinus thrombosis, meninigitis, subdural empyema and brain abscess . In the preantibiotic era, 20% of patients with orbital cellulitis had permanent loss of vision and 17% died for central nervous system complications, today these percentages decreased but have not still been eliminated (15 to 30% of patients develop visual sequelae) .
Orbital complication accounts for 74 - 85% of complications arising from acute sinusitis and usually this is secondary to acute ethmoidal sinusitis since the ethmoid sinus is separate from the orbit only by the papyracea lamina . In a paediatric series, Nageswaran et al. found that 98% and 71% of their patients with orbital cellulitis were affected by ethmoid or maxillary sinusitis respectively . Furthermore bilateral pansinusistis is the most common presentation . As in this case, an abscess may be present in the subperiostium of the lateral wall of the lamina papyracea . It was estimated that the incidence of a subperiosteal abscess in orbital infections is about 15% in children . The etiology of orbital cellulitis is usually unknown because blood cultures are often negative. Sinus cultures reveal typical acute sinusitis pathogens including Streptococcus pneumoniae, Haemophylus influenzae, Moraxella catharralis, Streptococcus pyogens, Staphylococcus aureus, α- and nonhemolytic streptococci and anaerobic bacteria of the upper respiratory tract . Subperiosteal abscess cultures showed S. pneumoniae, group A streptococci, H. influenzae, as the major pathogens in a previous paediatric series . Polymicrobial infections are also common and may be more frequent in older versus younger children .
The management of an “acute orbit” depends on the cause and severity of the infection. All patients affected by orbital cellulitis should be treated with intravenous antibiotics whereas they should undergo surgical drainage of abscesses and involved sinuses only in presence of large abscess, complete ophtalmoplegia or significant visual impairment, as in the our patient . Maxillo-facial CT scan is indicated to evaluate the extension of the infection and to identify children who are most likely to benefit from surgical intervention . Because of the aggressive nature of a subperiosteal orbital abscess, we agree with Rahbar et al. in obtaining a CT scan even if the only presentation is preseptal cellulitis . In our case, CT images showed a massive involvement of the paranasal cavities including the ethmoidal cells and the subperiosteal abscess of left orbit. Impairment of vision, periorbital erythema and hyperemia, proptosis, together with radiological findings, indicated an immediate surgical approach to avoid the potential loss of vision and the devastating morbidity associated to the subperiosteal orbital abscess . The surgical drainage of the abscess was afforded with FESS. This transnasal endoscopic technique provided a quick and safe drainage of the paranasal sinuses, orbita, anterior skull base avoiding facial scars as well as hastening the post-operative recovery period [11, 12]. Rahbar et al. found that orbital subperiosteal abscess in children can be successfully and safely managed by a transnasal endoscopic approach in selected patients . The choice of method of surgical drainage should be based on the location of the abscess and the experience of the surgeon. Medial and inferior orbital abscesses can be treated with an endoscopic approach while superior localization generally requests an external drainage.
After the emergency surgical treatment, a polispecialistic examination was immediately requested to choose the best antibiotic option, to examinate the dental status, and to exclude intracranial spreading of the infection. Considering this last complication, intravenous therapy with meropenem, a broad-spectrum antibacterial agent of the carbapenem family, was chosen. Meropenem is indicated as empirical therapy prior to the identification of causative organisms, or for disease caused by single or multiple susceptible bacteria in both adults and children with a broad range of serious infections .
The dental status was evaluated since the odontogenic nature of the sinusal and orbital infection has to be excluded, especially when the localization is monolateral. Finally, the intracranial spreading of the infection was excluded by A-MRI.
The result of the microbiological analysis (positive for GAS) led to consider a strong correlation between the pharyngitis and the sinusal/orbital involvement and to discharged the patient with the final diagnosis of left orbital cellulitis with periorbital abscess, endophtalmitis and acute pansinusitis as a consequence of GAS pharyngitis.
Group A streptococcal pharyngitis is usually a self-limited disease, and therapy can generally be safely postponed for up to 9 days after the onset of symptoms to prevent the occurrence of major nonsuppurative sequelae. However, according to guidelines of the Infectious Diseases Society of America, early initiation of antibiotic therapy results in faster resolution of signs and symptoms . Furthermore a Cochrane review of randomized, placebo-controlled trials showed that antibiotic therapy significantly reduces the risk of acute otitis media (relative risk 0.30; 95% CI, 0,15-0.58) and peritonsillar abscess (relative risk 0.15; 95% CI, 0.05-0.47) . Thus, antimicrobial therapy is recommended for subjects with symptomatic pharyngitis in the presence of GAS in the throat confirmed by culture or RADT . Clinical scoring systems have been developed to predict the likelihood of streptococcal infection among children and adults with sore throat . Presence of fever (temperature > 38°C), absence of cough, tonsillar swelling or essudate, tender and enlarged anterior cervical lymphnodes are correlated to approximately 30 to 50% probability of positive results of a throat culture or RADT. In this case, despite the clinical presentation, the streptococcal infection was not previously diagnosed. However, the serious complications seen in the patients are usually unexpected in a 15-years immunocompetent girl although it has been recently observed an increase in the incidence of head and neck infections especially associated with acute sinusitis due to group A streptococcal infections in children . This trend may reflect an increase of virulence related to the evolving biology of streptococcal organism and can justify the onset of aggressive and rapidly progressive infections also in previously health children. Much of the increase in invasive dissemination of Streptococcus Pyogenes (noted in last 15 years) has been associated with M protein types M1 and M3 that prevent phagocytosis of the bacteria by inhibiting the interaction with complement .