# Acute complicated UTI
– Diagnosis w/ HPI/P + UA w/ pyuria, bacteriuria
– HPI/P: UTI (dysuria/incr. freq./suprapubic pain) + symptoms extend beyond bladder (e.g., fever> 99.9F, chills/rigors/AMS, flank pain, CVA tenderness)
– Labs: UA, UCx
– Dx: Imaging only if >48-72hrs symptoms and/or severe illness, recurrence
PLAN
– Dispo:
– Hospitalization criteria: SIRS/Sepsis, high fever (>101 F), marked debility, marked pain, inability to tolerate PO
– Outpatient management (s/p IVF, IV ABx in ER/clinic) w/ PO ABx
– Empiric ABx critical illness/or obstruction: meropenem 1g IV Q8hrs + vanc
– Empiric ABx non-critical, high MDR risk- BS ABx: cefepime 2g IV Q12hrs, pip/tazo 3.375g IV Q6hrs
– Empiric ABx non-critical, normal MDR risk- standard spectrum ABx: ceftriaxone 1g IV QD, pip/tazo, ciprofloxacin 500mg PO BID*, levofloxacin 750mg/IV QD
– ABx s/p culture: [] for 5-10 day regimen
# Suspected HIV Infection (ICD-10: Z11.4 – Encounter for screening for HIV; R75 – Inconclusive laboratory evidence of HIV; Z20.6 – Contact with and suspected exposure to HIV)
### Overview:
– HIV infection is caused by the human immunodeficiency virus, which targets CD4+ T lymphocytes, leading to progressive immunosuppression and increasing the risk of opportunistic infections and malignancies.
– Early diagnosis is critical for initiation of antiretroviral therapy (ART), reducing transmission, and improving long-term outcomes.
### Diagnostic Criteria:
– Clinical suspicion based on risk factors, clinical presentation, or incidental findings.
– Acute HIV infection (acute retroviral syndrome) (2-4 weeks after exposure):
– Flu-like symptoms: Fever, sore throat, fatigue, headache
– Generalized lymphadenopathy
– Maculopapular rash (common on the trunk, may involve palms/soles)
– Myalgia, arthralgia
– GI symptoms: Diarrhea, nausea
– Chronic HIV infection (asymptomatic or with persistent generalized lymphadenopathy):
– Progressive immune dysfunction leads to opportunistic infections or AIDS-defining conditions in advanced stages.
### Risk Factors:
– Unprotected sexual activity (especially anal or vaginal intercourse)
– Multiple sexual partners
– Men who have sex with men (MSM)
– Injection drug use or sharing needles
– Mother-to-child transmission during pregnancy, delivery, or breastfeeding
– Blood transfusions or organ transplants (rare in developed countries)
– Occupational exposure (e.g., needlestick injuries)
– History of sexually transmitted infections (STIs)
### Differential Diagnosis:
– Other causes of acute febrile illness:
– Viral infections: EBV (mononucleosis), CMV, influenza
– Bacterial infections: Secondary syphilis, sepsis
– Autoimmune diseases: Systemic lupus erythematosus (SLE)
– Causes of chronic immunosuppression:
– Malignancies (e.g., leukemia, lymphoma)
– Congenital immunodeficiencies
– Chronic steroid use or other immunosuppressive therapies
### Plan:
— Lab Orders:
– HIV Testing:
– HIV-1/2 antigen/antibody combination (4th generation) test: Detects both p24 antigen and antibodies; positive test requires confirmation.
– HIV RNA PCR (viral load): For early detection during the window period or confirmation of acute HIV.
– Western blot (if available): Previously used for confirmation but now less common.
– Baseline Tests for Positive HIV Diagnosis:
– CD4+ T-cell count: Assess immune status and disease stage.
– HIV viral load (HIV RNA): Monitor disease progression and treatment efficacy.
– HIV drug resistance testing: To guide ART selection.
– Other Screening:
– Hepatitis B and C serologies
– Syphilis testing (RPR or VDRL, confirmed by FTA-ABS or TPPA)
– Gonorrhea and chlamydia NAAT (urine or site-specific testing)
– TB screening (IGRA or PPD)
– Complete metabolic panel (baseline liver/kidney function)
– CBC: Evaluate for anemia, leukopenia, or thrombocytopenia
– Lipid panel and HbA1c: Assess cardiovascular and metabolic risk
— Imaging:
– Only if complications or opportunistic infections suspected (e.g., chest X-ray for pneumonia).
— Management:
— Acute Setting:
– Educate the patient on the importance of follow-up testing and care.
– If acute retroviral syndrome suspected, confirm with HIV RNA PCR while awaiting antibody results.
— Antiretroviral Therapy (ART):
– Initiate ART as soon as possible after diagnosis, regardless of CD4 count or symptoms.
– Initial regimen typically includes two NRTIs (e.g., tenofovir/emtricitabine) + one integrase inhibitor (e.g., dolutegravir or bictegravir).
— Preventive Care for HIV-Positive Individuals:
– Prophylaxis for opportunistic infections:
– Pneumocystis pneumonia (PCP): Start if CD4 <200 cells/µL (e.g., TMP-SMX 1 DS tab daily).
– Toxoplasmosis: Start if CD4 <100 cells/µL and seropositive for Toxoplasma (e.g., TMP-SMX 1 DS tab daily).
– Mycobacterium avium complex (MAC): Start if CD4 <50 cells/µL (e.g., azithromycin 1200 mg weekly).
– Vaccination: Administer age-appropriate vaccinations (e.g., hepatitis B, influenza, pneumococcal) based on immune status.
— Post-Exposure Counseling:
– Educate on transmission prevention (e.g., condom use, needle safety).
– Partner notification and testing.
— Monitoring:
– Follow-up HIV RNA and CD4 count 2-8 weeks after starting ART, then every 3-6 months.
– Monitor for ART side effects, adherence, and drug resistance.
– Regular STI screening every 3-6 months in high-risk individuals.
— Special Considerations:
– Pregnancy: Start ART immediately to reduce vertical transmission; avoid dolutegravir in the first trimester if possible.
– Occupational Exposure (PEP): Start post-exposure prophylaxis (e.g., tenofovir/emtricitabine + raltegravir) within 72 hours of exposure and continue for 28 days.
– PrEP (Pre-Exposure Prophylaxis): Offer to high-risk HIV-negative individuals (e.g., tenofovir/emtricitabine 1 tab daily).
# Sore Throat (Pharyngitis) (ICD-10: J02.9 – Acute pharyngitis, unspecified)
– Sore throat (pharyngitis) refers to pain or discomfort in the throat, often worsened by swallowing. It is a common condition that may be caused by viral, bacterial, or non-infectious etiologies.
– Most cases are viral and self-limiting, but distinguishing bacterial causes, such as group A Streptococcus (GAS), is important to prevent complications.
ETIOLOGY
— Infectious Causes:
– Viral (most common):
– Rhinovirus, adenovirus, influenza, parainfluenza, coronavirus
– Epstein-Barr virus (EBV, infectious mononucleosis): Sore throat with fatigue, lymphadenopathy, splenomegaly
– Herpes simplex virus (HSV): Vesicular lesions in the oropharynx
– Coxsackievirus (herpangina): Vesicles on the tonsils and soft palate
– Bacterial:
– Group A Streptococcus (Streptococcus pyogenes): Abrupt onset sore throat, fever, tonsillar exudates, anterior cervical lymphadenopathy
– Group C and G Streptococcus: Similar to GAS but less common
– Fusobacterium necrophorum (Lemierre syndrome): Rare, associated with septic thrombophlebitis of the internal jugular vein
– Neisseria gonorrhoeae: Consider in sexually active individuals
– Diphtheria (rare): Gray, adherent pharyngeal membrane
— Non-Infectious Causes:
– Allergic rhinitis or postnasal drip
– Gastroesophageal reflux disease (GERD)
– Irritants: Smoking, pollution, dry air
– Trauma: Foreign body, intubation
– Malignancy: Persistent sore throat, particularly in smokers or those with weight loss
DIAGNOSTIC CLUES:
— History:
– Viral:
– Gradual onset, concurrent URI symptoms (cough, rhinorrhea, conjunctivitis)
– Bacterial:
– Sudden onset, fever, absence of cough, anterior cervical lymphadenopathy, tonsillar exudates
– EBV (mononucleosis):
– Prolonged sore throat, fatigue, posterior cervical lymphadenopathy
– GERD:
– Sore throat worse in the morning, history of heartburn
— Physical Exam:
– Erythematous pharynx ± exudates
– Palatal petechiae (suggestive of GAS or mononucleosis)
– Tonsillar hypertrophy (severe in bacterial infections or mononucleosis)
– Lymphadenopathy (anterior cervical in GAS, posterior cervical in EBV)
– Rash: Sandpaper-like rash in scarlet fever (GAS)
—
DIFFERENTIAL DIAGNOSIS:
– Viral pharyngitis (most common overall)
– Group A Streptococcal pharyngitis
– Epstein-Barr virus (infectious mononucleosis)
– Peritonsillar abscess (unilateral swelling, “hot potato voice”)
– Lemierre syndrome (pharyngitis + septic thrombophlebitis of the internal jugular vein)
– Gonococcal pharyngitis (history of orogenital contact)
PLAN // MANAGEMENT
— Lab Orders:
– Rapid antigen detection test (RADT) for GAS: High specificity, immediate results.
– Throat culture: Gold standard for GAS diagnosis, particularly if RADT is negative in children or adolescents.
– Monospot test or EBV serologies: If mononucleosis suspected.
– CBC with differential: Atypical lymphocytosis suggests EBV.
– Consider gonococcal culture if sexual exposure is suspected.
— Imaging:
– Not routinely required unless complications suspected:
– Neck CT with contrast: If peritonsillar abscess, retropharyngeal abscess, or Lemierre syndrome is suspected.
— Management:
— Viral Pharyngitis:
– Supportive care:
– Hydration and rest
– Analgesics: Acetaminophen 500-1000 mg Q6-8H PRN or ibuprofen 400-600 mg Q6-8H PRN
– Warm saltwater gargles
– Lozenges or throat sprays (e.g., benzocaine)
– Avoid antibiotics.
— Group A Streptococcal Pharyngitis:
– Antibiotic therapy (reduces complications and symptoms):
– First-line: Penicillin VK 500 mg PO BID-TID for 10 days or amoxicillin 500 mg PO BID for 10 days
– Alternative (if penicillin allergy): Cephalexin 500 mg PO BID for 10 days (non-anaphylactic allergy) or clindamycin 300 mg PO TID for 10 days
– Single-dose IM benzathine penicillin G (1.2 million units) for poor adherence
– Symptomatic care as above.
— Infectious Mononucleosis:
– Supportive care only (hydration, analgesics).
– Avoid amoxicillin or ampicillin (can cause a rash in EBV patients).
– Restrict physical activity for 3-4 weeks to avoid splenic rupture.
— Peritonsillar Abscess:
– Urgent ENT consultation for drainage.
– Empiric antibiotics: Ampicillin-sulbactam (Unasyn) or clindamycin.
— Non-Infectious Causes:
– GERD: Proton pump inhibitors (e.g., omeprazole 20 mg PO QD).
– Allergies/postnasal drip: Antihistamines (e.g., loratadine 10 mg PO QD) and nasal corticosteroids (e.g., fluticasone).
— Monitoring:
– Reassess in 48-72 hours if symptoms worsen or do not improve with treatment.
– Evaluate for complications such as peritonsillar abscess or rheumatic fever in untreated GAS.
—
### Complications:
– Group A Strep:
– Rheumatic fever
– Post-streptococcal glomerulonephritis
– Scarlet fever
– Peritonsillar or retropharyngeal abscess
– Viral Pharyngitis:
– Secondary bacterial infection (rare)
– EBV:
– Splenic rupture
– Hemolytic anemia or thrombocytopenia
– Lemierre Syndrome:
– Septic emboli
—
### Red-Flag Symptoms (Urgent/Emergent):
– Severe unilateral throat pain with trismus (peritonsillar abscess).
– Neck swelling or stiffness, difficulty breathing (retropharyngeal abscess or Lemierre syndrome).
– Stridor or drooling (epiglottitis, airway compromise).
– Persistent fever despite appropriate therapy.
—
### Special Considerations:
– Children:
– Higher likelihood of GAS; consider testing and treatment even with milder symptoms.
– Pregnancy:
– Use penicillin or cephalosporins for GAS; avoid tetracyclines and fluoroquinolones.
– Immunocompromised patients:
– Broader differential, including fungal or atypical bacterial infections.
This tool is designed solely for educational purposes and should not, under any circumstances, be used for actual patient care or actual medical documentation. The information provided by this tool is not even close to a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Reliance on any information provided by this AI tool is solely at your own risk.
# Cellulitis
# Bacterial skin infection (Cellulitis, Cutaneous abscess, Acute lymphangitis)
– In ER, patient presenting w/ erythema, swelling, warmth, tenderness, often w/ fever/chills
– Key risk factors: skin trauma, chronic edema, venous insufficiency, immunosuppression
– Differential diagnoses (Ddx): deep vein thrombosis (DVT), stasis dermatitis, contact dermatitis, necrotizing fasciitis
– Red flags: rapid spread, systemic signs (high fever, hypotension), immunocompromised status, history of MRSA or recent hospitalization
– Reassuring findings: localized infection w/o systemic involvement, response to oral antibiotics
PLAN
– Diagnostics:
– CBC (w/ diff for leukocytosis)
– Blood cultures if fever >38.5°C or severe infection
– Consider wound culture in recurrent or non-healing cellulitis
– Imaging (abd/pelv CT, MRI) if deep infection or osteomyelitis suspected
– Antibiotics (ABx) selection based on severity and MRSA risk:
– Mild: Cephalexin 500mg PO QID or Dicloxacillin 500mg PO QID
– Moderate: Amoxicillin/clavulanate 875/125mg PO BID or TMP-SMX DS PO BID plus Cephalexin
– Severe (IV therapy): Vancomycin (dosing per renal function) or Daptomycin 4mg/kg IV Q24H
– Supportive care:
– Analgesia PRN (Acetaminophen or Ibuprofen)
– Elevation of affected limb to reduce edema
– Monitor for spread of infection: reassess in 24-48 hours
– Consider compression therapy post-resolution in chronic edema
– Complications to monitor:
– Septicemia, osteomyelitis, necrotizing fasciitis
– Limb thrombosis in severe cases
– Inpatient considerations for comorbid conditions:
– Adjust antibiotic therapy for renal or hepatic impairment
– Caution w/ drug interactions in patients on polypharmacy
– Duration of therapy:
– Typical course 5-14 days, depending on clinical response
– Extend duration in immunocompromised or if slow response
– Follow-up:
– Re-evaluate if no improvement within 48-72 hours
– Consider alternative diagnoses or referral to specialist if non-responsive
The exact diagnostic criteria for cellulitis include:
Cellulitis is primarily a clinical diagnosis
– Clinical diagnosis primarily based on physical exam findings:
– Erythema: Redness of the skin, often rapidly expanding.
– Edema: Swelling of the affected area.
– Warmth: The affected skin feels warmer than the surrounding areas.
– Tenderness or pain: The affected area is sensitive to touch and may be painful.
– Induration: Firmness of the skin when palpated.
– Additional supportive criteria, although not necessary for diagnosis, may include:
– Fever and/or chills, indicating a systemic response.
– Lymphangitic streaking: Red streaks extending from the affected area, suggesting lymphatic involvement.
– Regional lymphadenopathy: Swollen and tender lymph nodes near the affected area.
– Past history of similar episodes or predisposing factors like skin trauma, chronic edema, venous insufficiency, or immunosuppression.
– Important differentials to consider (not part of diagnostic criteria but essential for accurate diagnosis):
– Deep vein thrombosis (DVT)
– Stasis dermatitis
– Contact dermatitis
– Necrotizing fasciitis
– Laboratory and imaging tests are not routinely required but may be used to rule out other conditions or in severe or atypical cases:
– Complete blood count (CBC): May show leukocytosis in severe infection.
– Blood cultures: Recommended if fever >38.5°C or signs of severe infection.
– Imaging: Considered in cases where deep infection or osteomyelitis is suspected.
# Cat Scratch Infection
# Cat Scratch Disease, Bartonella henselae infection, Regional Lymphadenopathy
– In ER, patient presents w/ a history of cat scratch or bite, usually w/in 1-2 weeks prior
– Key features: localized papule at site of injury, followed by regional lymphadenopathy (tender, swollen lymph nodes near the scratch site)
– Ddx: Localized bacterial skin infections, lymphadenitis, tularemia, sporotrichosis
– Red flags: Systemic symptoms (fever >38.5°C, malaise), immunocompromised status, very young or elderly age, supraclavicular lymphadenopathy
– Reassuring findings: Localized lymphadenopathy w/o systemic symptoms, history of cat contact
Diagnostic criteria:
– Clinical diagnosis primarily based on history of cat contact and characteristic clinical presentation
– Serology for Bartonella henselae may confirm diagnosis but not routinely required
– Imaging (ultrasound or CT) may be indicated to evaluate lymphadenopathy or exclude other causes
PLAN
– Observation and symptomatic management in most cases:
– Warm compresses to affected area
– Analgesia PRN (e.g., Acetaminophen, Ibuprofen)
– Lymph node size re-evaluated in 3-4 weeks
– Antibiotics in severe cases or high-risk patients (immunocompromised, very young, elderly):
– Azithromycin 500mg PO on day 1, then 250mg PO QD for 4 days
– Alternatively, Doxycycline 100mg PO BID for 2-4 weeks (not in children <8 years or pregnant women)
– Complications to monitor:
– Encephalopathy, neuroretinitis, osteomyelitis, systemic Bartonella infection
– Inpatient considerations:
– Adjust antibiotic choice based on patient allergies and comorbid conditions
– Monitor for secondary infections or complications in hospitalized patients
– Coordination w/ infectious disease specialists for complicated cases
– Expected treatment timeframe:
– Symptomatic improvement typically within 2-4 weeks
– Antibiotic therapy duration: 2-4 weeks depending on severity
– Follow-up:
– Reassess in 3-4 weeks or earlier if symptoms worsen
– Consider alternative diagnosis if no improvement or worsening symptoms
The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) Score for Necrotizing Soft Tissue Infection includes the following parameters:
– C-reactive protein (CRP) level:
– Score 0: <150 mg/L
– Score 4: ≥150 mg/L
– White blood cell count (WBC):
– Score 0: <15 x 10^9/L
– Score 1: 15-25 x 10^9/L
– Score 2: >25 x 10^9/L
– Hemoglobin (Hb):
– Score 0: >13.5 g/dL
– Score 1: 11-13.5 g/dL
– Score 2: <11 g/dL
– Sodium (Na):
– Score 0: ≥135 mmol/L
– Score 2: <135 mmol/L
– Creatinine:
– Score 0: ≤141 µmol/L (or ≤1.6 mg/dL)
– Score 2: >141 µmol/L (or >1.6 mg/dL)
– Glucose:
– Score 0: ≤10 mmol/L (or ≤180 mg/dL)
– Score 1: >10 mmol/L (or >180 mg/dL)
A score of ≥6 is suggestive of necrotizing soft tissue infection and warrants further investigation and management.
The ALT-70 score for predicting lower extremity cellulitis includes the following parameters:
– Age:
– Less than 59 years = 0 points
– 60 years or older = 1 point
– White blood cell count (WBC):
– Less than 11,000 cells/mm^3 = 0 points
– 11,000 cells/mm^3 or more = 1 point
– Temperature:
– Less than 37.8°C (100°F) = 0 points
– 37.8°C (100°F) or higher = 1 point
– Heart rate:
– Less than 90 beats per minute = 0 points
– 90 beats per minute or more = 1 point
– Absence of asymmetric swelling in lower extremities:
– No = 0 points
– Yes = 1 point
The total ALT-70 score is the sum of these points. A higher score suggests a greater likelihood of lower extremity cellulitis. This scoring system aids in differentiating true cellulitis from its mimics.
# Pasturella Cellulitis
# Animal Bite Wound, Pasteurella multocida infection, Soft Tissue Infection
– Patient presents in ER post-animal bite, commonly cat or dog, w/ rapid onset of pain, erythema, and swelling at the bite site
– Risk factors: Animal bites, especially cat bites penetrating deep tissue; compromised skin integrity
– Ddx: Other bacterial infections from animal bites (e.g., Capnocytophaga, Staphylococcus, Streptococcus), abscess, tetanus risk
– Red flags: Rapid progression of symptoms, fever, lymphangitis, immunocompromised status
– Reassuring findings: Localized infection, absence of systemic symptoms
Diagnostic criteria:
– Pasteurella cellulitis typically presents within 24 hours post-bite
– Diagnosis largely clinical, based on history of animal bite and characteristic signs at bite site
– Culture from wound may confirm Pasteurella multocida
PLAN
– Initial Management:
– Thorough irrigation and debridement of the wound
– Tetanus prophylaxis if indicated
– Antibiotics:
– Amoxicillin-clavulanate 875/125mg PO BID for 7-14 days (first-line)
– For penicillin-allergic patients: Doxycycline 100mg PO BID or TMP-SMX DS PO BID + Clindamycin
– Analgesia:
– Acetaminophen or Ibuprofen PRN
– Complications to monitor:
– Abscess formation, osteomyelitis, septic arthritis, systemic infection
– Inpatient considerations:
– Admit if signs of systemic infection, rapid progression, or in immunocompromised patients
– IV antibiotics may be initiated: Ampicillin-Sulbactam or Ceftriaxone + Clindamycin
– Expected treatment timeframe:
– Antibiotic therapy for 7-14 days, based on clinical response and severity
– Follow-up:
– Re-evaluate within 48-72 hours; consider extending or changing antibiotics if no improvement
– Wound care follow-up for suture removal if applicable
This template provides a comprehensive yet succinct approach for managing Pasteurella cellulitis, emphasizing prompt and appropriate treatment, monitoring for complications, and considerations for inpatient management.