Preseptal and orbital infections are distinct diseases, in which orbital septum is the dividing reference point . Preseptal cellulitis is generally a mild condition but orbital cellulitis sometimes represents a serious complications such as visual loss [4, 5]. The differential diagnosis between these two conditions can be challenging, since the clinical manifestations such as induration or erythema with periorbital erythema and edema are similar. Clinical signs specifically suggesting post-septal involvement include proptosis, chemosis, ophthalmoplegia, or decreased visual acuity. However, periorbital edema can often limit physical exam and hinder ability to differentiate between the two . Therefore, if orbital cellulitis is suspected or if bedside examination cannot rule it out, a sinus CT with contrast is warranted within 24 h of presentation .
While there is no gender difference in preseptal cellulitis, orbital cellulite has been reported to be more common in male also more common in winter because of its association with upper respiratory tract and paranasal infections . In the series of Botting et al. consisting of 262 pediatric patients with periorbital infection, the frequency of preseptal cellulitis and orbital cellulitis were found 87% and 13% . In studies performed in our country reported that the frequency of preseptal cellulitis is between 81% and 88.9%, the frequency of orbital cellulitis is between 11.9% and 19% in admitted children with periorbital infections [14, 15]. The similarly ratio of preseptal cellulitis and orbital cellulitis detected in our study. In studies comparing age distribution of preseptal cellulitis and orbital cellulitis cases, it was reported that the mean age of patients with orbital cellulitis was higher than those with preseptal cellulitis [6, 16, 17]. In the study of Botting et al.,  while the mean age distribution in preseptal cellulitis/orbital cellulitis cases was 3.9 years/7.5 years, it was found to be 4.7/8.1 years in Demir et al. . Although the exact cause of advanced age cannot be explained, this may be attributed to the fact that rhinosinusitis is more common in the etiology of orbital cellulitis than preseptal cellulitis and that the aeration of the sinuses in the younger age group is not yet completed. The age of the patients with orbital involvement was larger than that of the patients without orbital involvement in our study, but this difference was not statistically significant. Male gender was found to be more frequent in patients with or without orbital involvement [5, 15]. While the male/female sex ratio was 1.4/1 in orbital involvement, it was 1.5/1 in our patients with preseptal cellulitis cases. There are also higher rates of male dominance reported by Nageswaran et al., that the mean age of 7.5 years and a male/female ratio of 2.7/1 in 41 patients under 18 years of age with orbital cellulitis .
The most common etiologic cause was sinusitis in the whole patient group. While sinusitis was detected in all orbital cellulitis group, it was found in approximately half of the preseptal cellulitis group. In the literature, it is reported that 75% of orbital infections are associated with sinusitis and most commonly with ethmoid sinusitis [15, 17–19]. However, there are also studies in which the incidence of sinusitis is lower in patients with preseptal cellulitis [5, 14]. Similarly to our results Nageswaran et al. reported that all patients with orbital cellulitis was associated with sinusitis .
CT is the most useful imaging method and the most widely accepted diagnosis in the diagnosis of sinusitis and in evaluating a patient with orbital infection, shows the presence of complications such as orbital abscess, subperiostal abscess [7, 20, 21]. Imaging should also be performed in patients who do not heal with intravenous antibiotic therapy and who cannot perform eye and visual examination effectively due to their age. CT has been found to be accurate for diagnosing orbital cellulitis and subperiosteal abscess, with reported accuracies ranging from 91 to 100% [22, 23]. It has been reported that imaging methods are used between 12% and 96% in preseptal and orbital cellulitis cases [5, 15–17]. Orbital cellulitis is reported to be most commonly associated with sinusitis especially ethmoid sinusitis [18, 19]. Botting et al. according to CT findings, ethmoid sinus involvement was 86% and maxillary sinus involvement was 60% in patients with postseptal cellulitis . In the study of Nageswaran et al. 98% ethmoid rhinosinusitis was found . Similar to our study, there are studies with high maxillary sinus involvement .
Intracranial complications are an important problem that should be evaluated in preseptal cellulitis and orbital cellulitis. In a review of 16 studies included 180 cases with intracranial complications due to sinusitis in childhood period, reported that the frequency of complications were subdural empyema (49%), epidural abscess (36%), cerebbral abscess (21%) and meningitis (10%) . MRI is the preferred method for detecting intracranial complications with MRI venography when cavernous sinus thrombosis is considered [7, 15, 20, 21, 25, 26]. MRI is more sensitive in evaluating orbital and intracranial complications of sinusitis . Although MRI recommended for cases in which there is either clinical or CT-based suspicion for intracranial complications. The dural contrast enhancement was detected by orbital MRI imaging in two patients in the preseptal cellulitis group and the diagnosis of meningitis in these children showed the importance of MRI in our study. It supported the information that MRI is more suitable for detecting intracranial complications due to sinusitis. Also orbital MRI findings were detected in three patients who had previously diagnosed sinusitis with CT and did not recover with antibiotherapy in our study. One patient had inflammation of the medial rectus muscle and two patients had inflammation and subperiostal abscess in the medial rectus muscle. The radiological findings of these cases confirm that MRI is a more sensitive method for evaluating orbital complications of sinusitis .
The pediatric subperiosteal abscess is considered an abscess pocket localized between the lamina papyracea and the periorbita. Although same authors accept to drain the for subperiosteal abscess in children as soon as possible , several authors pointed out the effectiveness of antibiotic therapy in children less than 9 years of age [10, 27]. In general, surgical treatment is mainly dependent on the presence of visual impairment, ophthalmoplegia and proptosis. The need for surgical treatment in subperiosteal abscess has been reported in 14–23% in various studies [5, 14, 17]. In our study, 3 patients with orbital subperiostal abscess (2.4% in the whole patient group and 25% in the orbital cellulitis group) underwent endoscopic drainage due to the need for surgical treatment and 4 patient successfully treated with systemic antibiotics alone. Recurrence of infection occured rarely in same cases [2, 28]. It is suggested that patients with chronic or recurrent infections and complications should undergo further investigation of their immunological status (e.g. IgG deficiency) .
In recently published studies, Nation et al. found that 43% (11 of 26) pediatric patients with abscesses ≥ 500 mm3 were still able to be managed medically . Le et al. reported that patients with larger subperiosteal abscess could be successfully treated with systemic antibiotics alone, choosing the abscess cut-off size of 3.8 mL. Specifically, if the subperiosteal abscess volume is < 3.8 mL, then the probability of surgery is 12%; if the subperiosteal abscess volume is > 3.8 mL, then the probability of surgery is 71% . Currently accepted that orbital cellulitis, particularly subperiosteal abscesses, in children is not an absolute indication for immediate surgical intervention. Conservative nonsurgical measures including close monitoring with antibiotics can be safe and effective if appropriately used, depending on patient characteristics, exam findings, clinical course, and imaging .
In some studies, it has been reported that fever at admission, high leukocyte count and C-reactive protein were associated with orbital involvement [2, 5, 31, 32]. Demir et al. compared to mean CRP value in orbital cellulitis group and the preseptal cellulitis group (CRP value 37.5 mg/L vs 13.5 mg/L, respectively) and were found to be significantly higher in orbital cellulitis group . However, Kocabas et al. found no statistically significant difference in terms of mean CRP levels in patients with orbital and preseptal cellulitis . In our study, it was found that the CRP value was significantly higher in orbital involvement on the other hand there was no relationship between orbital involvement and fever and leukocyte values.