Staphylococcal splenic abscess in a septicemic pediatric patient

Splenic abscess is a rare entity and occurs after trauma or as a result of systemic bacteremia. Splenic abscess is an uncommon surgical problem in pediatric age group and difficulty in diagnosis in this group is because of rarity, insidious onset, and nonspecific clinical picture. Splenic abscess, found mostly in autopsies and progressing rather fatally, can be diagnosed and treated earlier with the help of recently developed radiological techniques. Patients, as seen in our case, are mostly admitted to the hospital with nonspecific complaints of abdominal pain and vomiting. It has a high rate of mortality when it is diagnosed late. Early diagnosis, prompt treatment, and splenic preservation as a goal in children should be considered unless there are multiple abscesses and nonresponsiveness to conservative regimen.

Keywords: Pediatric, Polymicrobial, Splenic Abscess

Splenic abscess is an infectious suppurative process involving an identifiable filling defect, either in parenchyma of spleen, or in subcapsular space. About 600 cases have been described so far in literature. Splenic abscess is a rare entity, with reported frequency in autopsy series between 0.14 and 0.7%. ^[1] It occurs after trauma or as a result of systemic bacteremia. ^[2] Previous studies have emphasized polymicrobial nature of these infections in 10 to 15% of patients. ^[3] Gram-negative aerobic bacteria are the most frequently reported isolates. ^[2] More recently, hematogenous seeding from septic foci has been the most common cause of splenic abscess, whereas the predisposing factors have been endocarditis, closed splenic trauma, and sickle anemia. ^[4] Clinical manifestations usually include fever, nausea, anorexia, and abdominal pain more intensely described in the upper left-quadrant area. Laboratory findings are consistent with acute phase of infection, but their exact nature is determined by the pathogen isolated from the abscess. Various conditions interfere with the prognosis of splenic abscess, such as underlying diseases, abscess number and size, organism spectra, therapeutic methods, and general conditions. Splenic abscess is an uncommon surgical problem in pediatric age group ^[5] and difficulty in diagnosis is because of rarity, insidious onset, and nonspecific clinical picture. This is a rare case of septicemia in splenic abscesses with Staphylococcus aureus from a pediatric patient.

A 12-year-old male child having high-grade fever and vomiting with vague left upper quadrant pain for last 3 days was admitted in emergency surgical ward of Guru Tegh Bahadur Hospital, Delhi. There was no history of jaundice, cough, breathlessness, joint pain, bleeding from any site, and altered sensorium. On examination, patient was conscious with normal vitals, febrile with mild pallor and dehydration. On per abdomen examination, there was no distension, visible peristalsis, tenderness, or rub over the spleen, but guarding was present. Liver and spleen were just palpable. With a provisional diagnosis of enteric fever, patient was investigated and hemoglobin was 9.6 mg/dl, total leukocyte count was 17 200/mm ³ , and differential leukocyte count were polymorphs-85%, lymphocytes-10%, monocytes-3%, and eosinophill-2%. The blood urea and serum electrolytes were normal and widal was negative. Peripheral smear did not show malarial parasite. Chest X-ray was normal. Ultrasonography (USG) of abdomen revealed liver with normal size and echo pattern; spleen showed multiple hyperechoic, space occupying lesions (SOL) with ill-defined margins of variable sizes. Computed tomography (CT) scan revealed three abscesses in spleen. Aspiration of the abscess was performed under CT guidance and the material obtained was cultured. Pus culture was sterile; AFB (acid fast bacilli) and Gram stain did not reveal any organism. Histopathology showed necrotic material with inflammatory infiltration consisting of polymorphonuclear cells, vascular dilatation, and fibroblastic proliferation. The patient was diagnosed as a case of splenic abscess, and was treated with ciprofloxacin and metronidazole. After two weeks of treatment, abdominal tenderness and guarding decreased, but fever persisted. Repeat USG after one week revealed a normal liver but persistence of splenic SOL. Clinically, spleen size remained 2 cm below the costal margin. As fever continued, the patient was transferred to pediatrics ward where blood culture revealed S. aureus sensitive to cloxacillin, cephalexin, erythromycin, gentamicin, and cotrimoxazole. Child was treated with appropriate antibiotics and was cured within two weeks. Splenectomy was not done, as it was not indicated. A follow-up session after 1 year revealed complete resolution of all symptoms.

Splenic abscess, found mostly in autopsies and progressing rather fatally, can be diagnosed and treated earlier with the help of recently developed radiological techniques.

Reports on splenic abscess between 1900 and 1995 showed great variety of causative pathogens with wide range of demographic and clinical conditions. ^[2] Splenic abscess is a relatively rare lesion, as shown by a recent study which reports splenic abscess frequency at 0.9% of 41 splenectomy materials that came to their department between 1997 and 2004. ^[1] Usual cause of splenic abscess is hematogenous seeding of spleen from an infective focus elsewhere. The most frequent agent found in the splenic abscess are Streptococcus, Staphylococcus, and microorganisms from the Enterobacteriaceae family. ^[5] Besides these, several cases of splenic abscesses are also reported to be caused by Chlamydia pneumoniae,  Brucella ^{More Details} spp., Clostridium spp., or even other microorganisms such as fungi. ^[1] Earlier studies, however, have shown Staphylococci species (primarily S. aureus) as the most frequently reported isolates. ^[3],[6]

The diagnosis of splenic abscess is often not considered in children due to its rarity and nonspecific clinical features and it accounts for only 15% of all cases. ^[7] The age of our patient however is not consistent with the peak age group for initial diagnosis of splenic abscesses described in the literature. From an epidemiological point of view, they are more frequently detected in middle-aged and older individuals, with no obvious preference for either sex. ^[8] Patients, as seen in our case, are mostly admitted to the hospital with nonspecific complaints of abdominal pain and vomiting, as described in the literature, and hence diagnosis of splenic abscess is not always easy. It has a high rate of mortality when it is diagnosed late. The most frequently observed laboratory finding of the cases with splenic abscess is leukocytosis, as found in our case and as reported by others also. ^[1] Splenic abscess can be identified by USG. However, USG cannot discriminate between abscess and infarct in some cases. CT is the examination of choice in which it appears as focal areas of low attenuation. In atypical cases, clinical presentation must be considered in order to make an accurate diagnosis. Although splenectomy is the most preferred method of treatment, recently, medical treatment and abscess drainage are proved to be efficient methods in the treatment of splenic abscess, especially in solitary, thick-walled cases of abscess. Although the drainage of pus is often required as part of the treatment, but in this case, administration of antibiotics was effective. Recent reports have stressed the changing clinical spectrum and treatment of splenic abscesses. The high mortality associated with delayed diagnosis emphasizes the need for prompt detection and early treatment. It would seem rather that because of the unique position of the spleen as a filtering organ for organisms, any pathology which diminished this function would render it open to invasion and abscess formation. Various theories have been advanced to explain the mode of formation of the splenic abscess. Arterial dissemination of an infected embolus from a distant focus, septicemia or pyemia, may give rise to septic infarction of branches of the splenic artery, as it appears in our case also. The primary source of the organism was never discovered in these cases.

Spleen abscess is still potentially a life-threatening disease, despite advances in the diagnosis and treatment. Patients presented puzzling signs and symptoms that impeded an accurate and prompt diagnosis. The nonspecific nature of the signs and symptoms of splenic abscess make imaging studies a cornerstone of diagnosis and newer imaging modalities, USG, computerized tomography, and the successful application of percutaneous aspiration and percutaneous closed drainage have changed approaches to diagnosis and therapy. The triad of fever, left upper quadrant pain, and a tender mass has been suggested as an important complex. For this reason, it should be considered, especially in cases with malignancy, persistent fever, and left upper quadrant pain. Early diagnosis, prompt treatment, and splenic preservation as a goal in children should be considered unless there are multiple abscesses and nonresponsiveness to conservative regimen.

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/1755-6783.85765