"Demodicosis" Mimicking PreSeptal Cellulitis: Severe Periocular and Facial Inflammation Caused by "Normal" Skin Flora.

Due to their relatively high prevalence and commensalism, the pathogenicity of Demodex mites has been debated. Recent data, however, show Demodex to be associated with skin and ocular surface diseases such as rosacea, blepharitis, and keratitis. Here the authors report the first known case, to the best of the their knowledge, of Demodex infestation mimicking preseptal cellulitis in an adult human. A 29-year-old male bilaterally blind from advanced retinopathy of prematurity presented with a 2-month history of right-greater-than-left upper eyelid and periocular/cheek swelling, redness, and ocular discharge that did not resolve with oral antibiotics or oral steroids. Based on MRI findings, biopsies of the right lacrimal gland, right orbital fat, and right upper eyelid preseptal skin were obtained which revealed marked intrafollicular Demodex mite density and budding yeasts in the upper eyelid skin. This case serves to alert clinicians to this entity that may not otherwise be usually considered in ophthalmic clinical practice.

Orbital aspergillosis in an immunocompromised man with no history of trauma: a case report.

Fungal orbital cellulitis is usually seen in immunocompromised individuals, and opportunistic pathogens are the main etiology. We herein report a case of fungal orbital cellulitis due to Aspergillus in a patient with no history of trauma. A 48-year-old man presented to the emergency room of our hospital with a 2-week history of periorbital swelling, conjunctival hyperemia, and chemosis of his right eye. The visual acuity of his right eye was 6/20, and the intraocular pressure was 44 mmHg. The main clinical findings were proptosis of the right ocular globe with conjunctival hyperemia and a palpable infratemporal orbital mass. Laboratory testing failed to detect the presence of a pathogenic infection, and the lesions on computed tomography images resembled those of a malignant tumor of the orbit. The diagnosis was finally confirmed by postoperative pathological examination, and the patient responded favorably to debridement combined with antifungal therapy. Histopathological examination may help to reveal the nature of this disease. Surgical removal of inflammatory lesions can serve as an important diagnostic and treatment method for fungal orbital cellulitis.

Periorbital cellulitis as the initial presentation of acute lymphoblastic leukaemia.

A girl in early childhood with no significant medical history developed left eye periorbital oedema and erythema. She was treated with intravenous antibiotics for suspected severe periorbital cellulitis. Despite treatment, the patient's cellulitis progressed into necrotising fasciitis, and she was transferred for ophthalmology review and imaging. A CT scan and eye swab culture-confirmed Staphylococcus aureus periorbital cellulitis. Incidentally, pathology revealed significant pancytopenia suspicious of leukaemia. The patient underwent bone marrow biopsy and was diagnosed with B-cell acute lymphoblastic leukaemia (ALL). A multidisciplinary specialist assessment revealed no ocular evidence of leukaemia and no intraocular concerns. In medical literature, it is consistently found that cases of ALL initially manifesting as proptosis or eyelid oedema are invariably due to neoplastic infiltration. This case represents unique documentation where periorbital cellulitis is the initial presentation of B-cell ALL, underscoring the necessity to consider periorbital cellulitis as a possible differential diagnosis in ophthalmic manifestations of ALL.

Management of oculo-orbital complications of odontogenic sinusitis in adults.

Introduction: Odontogenic maxillary sinusitis (OMS) is an infectious inflammatory pathology caused by a dental condition. Considering the anatomical relations with the orbit, maxillary sinus infection can easily spread, evolving into severe oculo-orbital complications that can sometimes be life-threatening. Material and methods: We performed a retrospective study of over 2 years, examining the data of 18 patients diagnosed with OMS with oculo-orbital complications. The patients were evaluated regarding their dental history, symptoms, clinical and endoscopic findings, ophthalmologic evaluation, bacteriologic tests, computed tomography (CT) imaging, medical and surgical treatment, and outcomes. Results: The age of the patients was between 24 and 65 years old with an almost equal gender distribution: 10 female and 8 male patients. From the total, 7 patients had type II diabetes, 2 of whom were insulin-dependent, 1 patient had thrombophilia and 2 patients had renal failure with peritoneal dialysis. Regarding the type of oculo-orbital complications, 10 patients were diagnosed with preseptal cellulitis and 8 with orbital cellulitis. Just 5 patients with orbital cellulitis required surgical treatment and orbitotomy was performed, followed by endonasal endoscopic drainage. The evolution after surgical treatment was favorable for all operated patients. Discussions: Oculo-orbital complications of OMS are typically more severe than those of rhinogenic sinusitis because anaerobic bacteria are involved. Immunosuppression represents a favorable environment for the development of OMS and its complications, diabetes being the most common risk factor. A negative prognostic feature is the appearance of ophthalmological symptoms in both eyes, so visual function may be reduced. The treatment of oculo-orbital complications of OMS is urgent and depends on a broad-spectrum antibiotic therapy associated or not with surgical intervention. Conclusions: The diagnosis of oculo-orbital complications of OMS is complex and requires clinical experience as well as extensive medical knowledge to treat both the cause and the consequences of the conditions quickly and effectively. The proper management of oculo-orbital complications is based on a multidisciplinary team: ophthalmology, ENT, dentistry, imaging, and laboratory. Abbreviations: OMS = odontogenic maxillary sinusitis, CT = computed tomography, ENT = ear-nose-throat, MRI = magnetic resonance imaging, HNS = head and neck surgery.

Superior Ophthalmic Vein Thrombosis: A Case Report in a Previously Healthy Methicillin-Resistant Staphylococcus aureus-Positive Patient.

BACKGROUND Superior ophthalmic vein thrombosis (SOVT) is a rare condition, with an incidence of 3 to 4 cases per million per year. SOVT can be classified according to the underlying etiology into septic or aseptic SOVT. We present a case of right SOVT in a previously healthy patient with a positive blood culture of methicillin-resistant Staphylococcus aureus (MRSA). CASE REPORT A previously healthy 38-year-old female patient presented with a 2-week history of worsening right-sided headache associated with photophobia, phonophobia, right-sided ear pain, and tinnitus. The best corrected visual acuity was 6/12 in the right eye and 6/6 in the left eye. Ophthalmic examination revealed right eye upper lid edema, proptosis, and diplopia in all gazes, mainly vertical. The fundus examination showed a raised hyperemic right optic disc with blurred margins. Laboratory investigations showed a positive blood culture of MRSA and elevated levels of inflammatory markers erythrocyte sedimentation rate and C-reactive protein. Orbital computed tomography examination showed periorbital and orbital cellulitis with superior ophthalmic vein thrombosis. The patient was treated successfully with antibiotics and anticoagulants. At 1-month follow-up, the patient was compliant with medications and reported full resolution of symptoms, with no visual acuity impairment. CONCLUSIONS SOVT is a challenging ophthalmic condition and can be present concurrent with orbital cellulitis or cavernous sinus thrombosis. Early imaging studies and proper management are important to prevent serious complications. Ophthalmologists need to be alerted of the importance of tailoring antibiotics based on the causative agent, to decrease the risk of therapeutic failure and microbial resistance.

Orbital abscess with white eye in patients treated with oral antibiotics for orbital cellulitis.

PURPOSE: To report a case series of seven patients with late presentation of orbital/subperiosteal abscess following oral treatment of orbital cellulitis. METHODS: A retrospective case series of all patients presented with orbital abscess following oral treatment of orbital cellulitis from two tertiary-care eye centres in Riyadh, Saudi Arabia, was conducted. Demographic profiles, risk factors, initial clinical presentation, management regimens, and final outcome were analysed. RESULTS: Patients presented mainly with proptosis and limitation of extraocular motility without external ophthalmic inflammatory signs. Most patients needed surgical evacuation despite the appropriate initiation of intravenous antibiotics following presentation to our hospitals. CONCLUSION: Treating orbital cellulitis with oral antibiotics may lead to delayed presentation of orbital abscess without external ophthalmic inflammatory signs.

Role of Acute Rhinosinusitis in Periorbital Infections in Children.

OBJECTIVE: Periorbital cellulitis in children are commonly caused by acute rhinosinusitis (ARS). This study investigated the association of ARS and the severity of periorbital cellulitis in children. STUDY DESIGN: Retrospective case-control study of children with periorbital cellulitis with ARS versus periorbital cellulitis without ARS. SETTING: Patients were seen at West Virginia University Children's Hospitals between August 2011 to August 2022. METHODS: Patients were divided into cases and controls based on presence or absence of ARS. ARS was defined based on clinical symptoms with objective presence of disease on CT scan. Patients' characteristics, treatment, hospital length of stay, and readmission were collected. RESULTS: The sample consisted of 118 pediatric patients with orbital cellulitis. Patients with ARS were younger than patients without ARS (6.3 vs 8.5, p = 0.025), however there were no sex differences between two groups (p = 0.540). The ARS group had higher incidence of postseptal cellulitis (51.5% vs 9.6%, p < 0.001). As compared to patients without ARS, patients with ARS were more likely to be admitted (p < 0.001), have a longer length of stay (median of 3.5 days vs 0.5 days, p < 0.001), require IV antibiotics (95.3% vs 54.9%, p < 0.001), and require surgical intervention (23.1% vs 5.8%, p < 0.001). Readmission rate was similar between the two groups. CONCLUSION: Children presenting with acute periorbital cellulitis who have ARS tend to have more severe infection requiring higher level of care. ARS should be assessed and incorporated into the plan of care of pediatric patients with periorbital infections.

Pediatric orbital subperiosteal abscess outbreak in Iran: characteristics and causes.

PURPOSE: To evaluate demographics, characteristics, and management of pediatric patients with subperiosteal abscesses (SPA) secondary to orbital cellulitis and discuss the etiology of a dramatic rise in SPA. METHODS: Data were gathered by retrospective chart review of patients admitted to a tertiary referral eye hospital (Farabi Eye Hospital) diagnosed with orbital cellulitis with subperiosteal abscess from October 2022 to March 2023 (six months). Data on demographic information, clinical examination, radiographic evidence of sinusitis, orbital cellulitis, SPA, surgical and non-surgical management taken, isolated bacteria, and duration of hospital stay were gathered. RESULTS: 24 patients were admitted during these six months, with a diagnosis of orbital SPA secondary to paranasal sinusitis, confirmed by an orbital Computed Tomography (CT) scan. The age range was 11 months to 16 years. 75% of patients were male. All patients had a history of flu-like illness before developing orbital cellulitis. All patients had concurrent sinusitis, and 18 underwent initial surgical abscess drainage. The ethmoid sinus was the most involved, and most patients had a medially located SPA. Abscess volume ranged from 0.78 to 7.81 cm3 (mean: 3.52 cm3). One patient had concurrent central retinal artery occlusion due to orbital cellulitis. CONCLUSIONS: In this study, we report a dramatic increase in the incidence of SPA referred to our hospital. Larger abscess volumes and an increased number of cases that needed initial surgical drainage are also of note. An influenza outbreak in the autumn and winter, undiagnosed Corona Virus Disease 2019 (COVID-19) infection, increased antimicrobial resistance due to excessive off-label use of antibiotics during the COVID-19 pandemic, and more virulent bacterial infections are the most probable hypotheses to justify this observation.

Neutrophil-to-Lymphocyte Ratios Distinguish Idiopathic Orbital Inflammation From Orbital Infectious Disease.

PURPOSE: The neutrophil-to-lymphocyte ratio (NLR) is a relatively novel biomarker to distinguish between acute stresses. This study was performed to determine whether the NLR may discern infectious orbital maladies from idiopathic orbital inflammation (IOI). METHODS: The NLR was calculated by a review of the initial blood draws of adult patients who presented to the emergency department at a single academic medical center. Statistical comparisons were performed to identify the significance of these results. RESULTS: Ten patients with IOI, 12 patients with necrotizing fasciitis (NF), and 12 patients with orbital cellulitis (OC) presented to the emergency department. The groups were not statistically significantly different in terms of age or gender. The mean NLRs were 3.48 (standard deviation = 1.80), 13.5 (standard deviation = 14.5), and 8.15 (standard deviation = 6.56) for IOI, NF, and OC, respectively. Patients with IOI had statistically significantly lower NLRs than patients with NF ( p = 0.037) and OC ( p = 0.034). However, the NLRs of patients with OC were not statistically significantly different from those of patients with NF ( p = 0.27). CONCLUSIONS: The NLR appears to distinguish IOI from infectious etiologies, but does not discern between variants of infection. These results should be juxtaposed against appropriate imaging and clinical evaluations, but elevated NLR values may heighten clinicians' concerns for an infectious process and encourage them to initiate appropriate management steps.

Subperiosteal and Orbital Abscesses: A Comparison of Clinical Features, Management, and Outcomes.

PURPOSE: To compare the clinical features, management, and outcomes between orbital cellulitis patients with subperiosteal abscess (SPA) and those with orbital abscess (OA). METHODS: A retrospective study was conducted at a tertiary care center through medical record search to identify patients with orbital cellulitis from January 1, 2000 to December 31, 2022. Charts were screened for those with radiographic evidence of SPA or OA. Demographic data and presenting clinical features were compared between the 2 cohorts. Primary outcomes compared included rates of surgical intervention, reoperation, and readmission; and length of hospital stay and final vision. RESULTS: A total of 189 patients, 162 with SPA and 27 with OA, met the criteria. The OA group (mean 46.5 ± 18.6 years) was older than the SPA group (mean 19.1 ± 21.4 years). Comorbid sinusitis was significantly more common in the SPA cohort (95.7% SPA; 70.4% OA; p < 0.001), while OA was more likely to occur with orbital trauma (29.6% vs. 8.0%; p = 0.003), implanted hardware (11.1% vs. 0.6%; p = 0.005), and comorbid diabetes (22.2% vs. 4.3%; p = 0.001). OA patients more often presented with a relative afferent pupillary defect (21.7% vs. 3.9%; p = 0.005), vision worse than 20 of 50 (42.3% vs. 16.2%; p = 0.005), and methicillin-resistant Staphylococcus aureus infection (20.8% vs. 5.8%; p = 0.036). OA was associated with a higher reoperation rate (47.8% vs. 21.3%; p = 0.019), readmission rate (18.5% vs. 5.6%, p = 0.047), and limited extraocular motility at follow-up (4.3% vs. 25%; p = 0.013); while mean length of hospital stay and final visual acuity were similar. CONCLUSION: OA may affect an older population with a divergent risk factor profile compared with SPA. OA may cause more severe functional impairment on presentation, warranting more aggressive management to achieve visual outcomes similar to SPA.

Orbital Fat Density as a Diagnostic Tool in Pre-Septal and Orbital Cellulitis.

PURPOSE: To evaluate the usefulness of measuring orbital fat density in identifying post-septal involvement when initial differential diagnosis between orbital and periorbital cellulitis (OC and POC) is unclear. MATERIALS AND METHODS: Retrospective study of patients with clinical diagnosis of OC or POC who underwent contrast-enhanced computerized tomographic scans over a span of 10 years. Intraconal orbital fat density was measured with Hounsfield units (HU) in six areas on axial scans consisting of nasal and temporal intraconal sites. These measurements correlated with the initial and final diagnoses. Main outcome measures were HU values at the initial and final diagnoses. RESULTS: Fifty-seven patients were included. Mean HU measurement was -52 ± 18 HU for the involved side vs. -63 ± 13 for the uninvolved side (P < .001). The values were higher in cases of a final diagnosis of OC in the involved side (P < .001). The HU values were significantly higher in the nasal vs. the temporal locations of each orbit bilaterally (P < .001). The initial POC diagnosis of 20 patients (35%) was revised to OC. CONCLUSION: Intraconal fat density measurements can assist in the primary assessment of orbital involvement in patients with an uncertain initial diagnosis, with a HU value higher than -50 is suggestive of orbital involvement.

Orbital cellulitis with panophthalmitis and scleral necrosis - a case report.

BACKGROUND: Orbital cellulitis is common in young children and is often secondary to coexisting sinus disease. Coexisting orbital cellulitis and panophthalmitis is a rare clinical event and usually occurs secondary to trauma or from an endogenous source. CASE PRESENTATION: A febrile 2-year-old male presented with periorbital inflammation and exudative retinal detachment. Imaging showed acute sinusitis and extensive orbital cellulitis. Because of progressive scleral thinning, the patient underwent enucleation. CONCLUSION: We present a case of concurrent orbital cellulitis, panophthalmitis, and scleral necrosis in an immunocompetent pediatric patient. Timely intervention is important to prevent life threatening complications with the rare occurrence of coexistent orbital cellulitis and panophthalmitis.

Painless Orbital Bone Infarction in a Child with Sickle Cell Anemia: A Case of Misdiagnosed Periorbital Cellulitis.

BACKGROUND Sickle cell orbitopathy is a rare complication of sickle cell disease that closely mimics other conditions, such as orbital cellulitis and osteomyelitis. We report a case of painless orbital bone infarction masquerading as periorbital cellulitis in a child with sickle cell anemia. CASE REPORT A 4-year-old Saudi girl with sickle cell disease presented to our hospital with vaso-occlusive crisis characterized by bilateral lower limb pain and painless left orbital swelling. On examination, she had swelling of the left upper eyelid with redness and mild ptosis (margin reflex distance 1 was 2 mm) without proptosis. Magnetic resonance imaging with contrast showed bilateral sub-periosteal heterogeneous collections (2×0.8×2.1 cm in the superolateral wall of the left orbit and 1×0.6 cm in the inferolateral wall of the right orbit), with intermediate-to-high T1 signal intensity and high T2 signal, causing a mass effect on the adjacent superior and lateral rectus muscles. The patient was treated with systemic antibiotics and supportive treatment for vaso-occlusive crisis under the care of the pediatric team and was discharged without complications. CONCLUSIONS The diagnosis of sickle cell orbitopathy can be challenging, and an accurate diagnosis is essential to ensure appropriate management. Thus, we report the case of a 4-year-old child with painless sickle cell orbitopathy masquerading as pre-septal cellulitis.

Transnasal endoscopic drainage of neonatal orbital abscess.

Neonatal orbital complications are rare and potentially fatal, demanding prompt diagnosis and adequate treatment. A 25-day-old neonate presented with rapidly progressive orbital complications as evidenced by proptosis, chemosis, lid oedema and restricted eye movements, developing within 3 days. There was no significant medical history or risk factors for developing infection. An initial conservative approach with antimicrobial therapy failed to show any resolve. An MRI brain, orbits and paranasal sinuses demonstrated that there were features suggestive of right orbital cellulitis with possibility of abscess formation with right ethmoidal mucoinflammatory disease and mass effect on the optic nerve causing stretching and compression by the surrounding inflammation.The patient was treated successfully with transnasal endoscopic drainage and decompression. Endoscopic access was challenging owing to the restrictive anatomy. Postoperatively, the patient showed improvement, with gradual decrease in proptosis and resolve in eye movements.

Case Report: Vision Loss in a Child Caused by Streptococcus constellatus.

PURPOSE: We present a rare case of Streptococcus constellatus -induced odontogenic orbital cellulitis. METHODS: An 8-year-old boy presented to an outpatient clinic with complaints of right-sided toothache, right eye swelling, and decreased visual acuity. He was referred to a pediatric critical care department for further management. Comprehensive diagnostic assessments, such as ophthalmic examination, blood tests, computed tomography, and MRI, were performed. RESULTS: On presentation, the best-corrected visual acuities were 20/250 and 20/20 in the right and left eyes, respectively. Examination revealed grade 2+ eyelid edema and erythema and grade 4+ chemosis and exophthalmos in the right eye. The patient displayed restricted eye movements in all directions. Blood tests revealed a total white blood cell count of 12,100 cells/µL. Axial and coronal computed tomography revealed right-sided maxillary sinus, ethmoidal sinus, and orbital abscesses. Therefore, the patient was diagnosed with septicemia, orbital cellulitis, and orbital apex syndrome in the right eye. Intravenous antibiotics were administered; paracentesis of the orbital abscess was performed under local anesthesia. However, the patient's condition worsened, resulting in a complete loss of light perception in the right eye. Accordingly, surgery was performed under general anesthesia within 24 hours of admission; the surgery involved drainage of the orbital abscess through an inferior intraorbital incision, as well as drainage of the ethmoid sinus and maxillary sinus abscesses via nasal endoscopy. A culture obtained from the orbital abscess yielded S. constellatus . The infection was managed by a combination of surgical intervention, antibiotics, steroids, and hyperbaric oxygen therapy. However, because of optic nerve injury, vision in the affected eye partially recovered to 20/200. CONCLUSIONS: Streptococcus constellatus -induced pediatric orbital cellulitis can result in significant morbidity. The significant improvement in vision, from no light perception to 20/200, emphasizes the importance of timely diagnosis and treatment in patients who present with acute orbital cellulitis and vision loss symptoms.

Microbial patterns and culture utility in orbital cellulitis.

PURPOSE: To determine the prevalence and types of pathogens found in children with orbital cellulitis and to evaluate the utility of nonoperative cultures. METHODS: This was a retrospective cohort study of children with imaging-confirmed orbital cellulitis over a period of 8 years. Outcomes included prevalence and types of organisms, polymicrobial infection, mixed aerobic-anaerobic infection, effect of age, and culture utility. RESULTS: Of 220 children with orbital cellulitis, 112 (51%) had cultures taken; 69 (31%) had surgical intervention. Culture sources for the 112 children with cultures included blood (57 patients [51%]), sinus (53 [47%]), orbit (42 [38%]), brain (6 [5%]), and skin/conjunctiva/lacrimal sac (6 [5%]). Streptococcus anginosus group strains grew in cultures from 19 children (17%); methicillin-sensitive Staphylococcus aureus (MSSA), in 15 (13%); Streptococcus pyogenes, in 12 (11%); methicillin-resistant Staphylococcus aureus (MRSA), in 6 (5%); anaerobic/facultative gram negative rods, in 8 (7%); anaerobic Gram-positive cocci, other Viridans group streptococci, and Streptococci pneumoniae, in 3 (3%) each; and normal respiratory/skin flora, in 23 (21%). Polymicrobial infection (P = 0.08) and anaerobic organisms (P = 0.58) did not differ by age (range, 0.1-16.8 years). In all 220 (100%) children, nonoperative cultures were either not obtained (108 [49%]), not helpful in avoiding surgery (69 [31%]), showed no growth (39 [18%]), or grew an organism that did not change management from empiric therapy (4 [2%]). CONCLUSIONS: While many organisms may be cultured from children with orbital cellulitis, Streptococcus and MSSA were the most common in our study cohort. MRSA is uncommon, so initial empiric coverage is not necessary. Rates of polymicrobial and anaerobic infection were similar across ages. Our results indicate that nonoperative cultures are not indicated in the initial medical management of orbital cellulitis; in our cohort, they neither resulted in treatment changes nor helped avoid surgery.

Bacterial orbital cellulitis - A review.

Infections of orbit and periorbita are frequent, leading to significant morbidity. Orbital cellulitis is more common in children and young adults. At any age, infection from the neighboring ethmoid sinuses is a likely cause and is thought to result from anatomical characteristics like thin medial wall, lack of lymphatics, orbital foramina, and septic thrombophlebitis of the valveless veins between the two. Other causes are trauma, orbital foreign bodies, preexisting dental infections, dental procedures, maxillofacial surgeries, Open Reduction and Internal Fixation (ORIF), and retinal buckling procedures. The septum is a natural barrier to the passage of microorganisms. Orbital infections are caused by Gram-positive, Gram-negative organisms and anaerobes in adults and in children, usually by Staphylococcus aureus or Streptococcus species. Individuals older than 15 years of age are more likely to harbor polymicrobial infections. Signs include diffuse lid edema with or without erythema, chemosis, proptosis, and ophthalmoplegia. It is an ocular emergency requiring admission, intravenous antibiotics, and sometimes surgical intervention. Computed tomography (CT) and magnetic resonance imaging (MRI) are the main modalities to identify the extent, route of spread from adjacent structures, and poor response to intravenous antibiotics and to confirm the presence of complications. If orbital cellulitis is secondary to sinus infection, drainage of pus and establishment of ventilation to the sinus are imperative. Loss of vision can occur due to orbital abscess, cavernous sinus thrombosis, optic neuritis, central retinal artery occlusion, and exposure keratopathy, and possible systemic sequelae include meningitis, intracranial abscess, osteomyelitis, and death. The article was written by authors after a thorough literature search in the PubMed-indexed journals.

Serologic Evaluations in the Distinction Between Sinusitis-Related Orbital Cellulitis and Periorbital Necrotizing Fasciitis.

PURPOSE: While sinusitis-related orbital cellulitis (SROC) and periorbital necrotizing fasciitis (PNF) share similar clinical presentations, they are managed differently, making rapid recognition of the appropriate clinical entity critical to optimal outcomes. This study was performed to assess whether serologic testing might help clinicians to distinguish between SROC and PNF. METHODS: A retrospective review analysis was used to compare initial complete blood counts and comprehensive metabolic panels among adult patients with SROC and PNF. Statistical evaluations were used to determine the significance of differences between the groups. RESULTS: Thirteen patients with PNF and 14 patients with SROC were identified. The 2 groups were similar in age, gender, and likelihood of immunosuppression ( p > 0.05 for each metric). Mean leukocyte counts were 18.52 (standard deviation = 7.02) and 10.31 (standard deviation = 5.77) for PNF and SROC, respectively ( p = 0.0057). White blood cell levels were above normal limits for 12 patients with PNF (92.3%) and 7 patients with SROC (50%) ( p = 0.017). No other laboratory test was significantly different between the 2 groups. CONCLUSIONS: While the majority of serologic testing was quite similar in patients with either SROC or PNF, leukocyte levels may represent an important clue to distinguish between the two diseases. Clinical evaluation remains the gold standard to make the proper diagnosis, but markedly elevated white blood cell counts should prompt clinicians to at least consider a diagnosis of PNF.