Showing posts with label Infectious diseases. Show all posts
Showing posts with label Infectious diseases. Show all posts

Saturday, April 15, 2017

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Emphysematous pyelonephritis - Review

 DEFINITION 
Emphysematous pyelonephritis is an acute necrotizing infection characterized by gas formation.
It is characterized by the presence of gas in and around the kidney.

 ETIOLOGY 
E. coli (58%) and K. pneumoniae (21%) are the organisms most commonly isolated. Clostridium and Enterobacter spp may also be responsible, 7% each.

 RISK FACTORS 
1) Diabetes mellitus (70-90%)- usually patients with poor glucose control. High levels of glucose in the urine serve as a substrate for these bacteria and large amounts of gas are generated through natural fermentation
2) Obstruction (25-40%)- it is another common predisposing factor for emphysematous pyelonephritis.

For non-diabetics, protein fermentation is a proposed source of gas formation.

 CLINICAL FEATURES 
7% of cases may be asymptomatic.
If symptomatic, patients may complain of pneumaturia, irritative lower tract voiding symptoms, flank pain or may present in a severe septic condition with an acute abdomen and high grade fever.

 DIAGNOSIS 
1) Plain radiograph of the abdomen can help us in 80-85 % of cases.
2) CT is considered the optimal imaging technique for confirming emphysematous infection and characterizing the extent of involvement.

According to radiological findings and CT scans, emphysematous pyelonephritis can be classified as follows:
Class 1— gas confined to the collecting system
Class 2— gas confined to the renal parenchyma alone
Class 3A— perinephric extension of gas or abscess
Class 3B— extension of gas beyond the Gerota fascia
Class 4— bilateral EPN or EPN in a solitary kidney
Emphysematous pyelonephritis

 Plain abdominal radiograph showing presence of air around the left kidney

Emphysematous pyelonephritis
 CT scan showing left emphysematous pyelonephritis with presence of gas and parenchymal destruction
Emphysematous pyelonephritis
CT scan of a diabetic patient with emphysematous pyelonephritis due to uncontrolled diabetes and renal stones.


 MANAGEMENT 
1) Medical management includes antimicrobial therapy, bladder drainage and glycemic control.   effective.
2) Surgical intervention usually is required for only 10% of the cases. Emergency nephrectomy was traditionally considered necessary but currently, percutaneous drainage is the recommended initial approach.

 Later, elective nephrectomy may be required for some patients.


First published on: 15 April 2017

Friday, June 10, 2016

The common cold - definition, diagnosis and treatment

 DEFINITION 
It is an upper respiratory tract illness that comprises of rhinorrhea and nasal obstruction as the main symptoms.

 EPIDEMIOLOGY 
5- 7 times/ year in children and 2-3 times/ year in adults.
most commonly seen between the early fall and late spring in temperate climates.
Transmission of the virus may occur via direct contact, large-particle aerosol, or small-particle aerosol.

 MICROBIOLOGY 
The rhinoviruses are usually responsible for the majority of cases. Coronavirus, respiratory syncytial virus and metapneumovirus may also be associated with the common cold syndrome.

 DIAGNOSIS 
The diagnosis of the common cold is a clinical diagnosis. Polymerase chain reaction assay can determine the responsible pathogen but this is rarely useful in the management of the patient.



 THERAPY 
Management is mainly directed towards the bothersome symptoms as no specific antiviral agents are useful in the treatment.


First published on: 10 June 2016

Friday, January 23, 2015

A case of Mycobacterium marinum infection in a fisherman

Historically recognized as “swimming pool” or “fish tank” granuloma.

Clinical features:
Most infections occur 2 to 3 weeks after contact with contaminated water from one of these sources. The lesions are most often small violet papules on the hands and arms that may progress to shallow, crusty ulcerations and scar formation. Lesions are usually singular. However, multiple ascending lesions resembling sporotrichosis can occasionally occur.
Most patients are clinically healthy with a previous local hand injury that becomes infected while cleaning a fish tank or patients may sustain scratches or puncture wounds from saltwater fish, shrimp, fins and other marine life contaminated with
M. marinum. Swimming pools seem to be a risk only when non-chlorinated.

Diagnosis:
Diagnosis is made from culture and histologic examination of biopsy material, along with a compatible history of exposure.

Treatment:

No treatment of choice is recognized for M. marinum. However, successful treatments have traditionally been a two-drug combination of Rifampin (600 mg/day) plus Ethambutol (15mg/Kg) or monotherapy with Doxycycline, Minocycline (100 mg BD), Clarithromycin (500mg BD) or Trimethoprim-Sulfamethoxazole given for a minimum of 3 months. Clarithromycin has been used increasingly because of good clinical efficacy and minimal side effects, although published experience is limited.








The following is the case of a fisherman who got injured while handling his fishing cage and presented with extensive papular lesions on his forearm. He was started on two drug-combination therapy for 5 months.











The second image is the same patient after 3 months of treatment.