Chief Complaint: Recurrent Infections
A. History: Skin Infection
| Next Pivotal Assessment | Findings |
|---|---|
| Culture and Sensitivity | Methicillin Resistant Staphylococcus Aureus |
Determining the cause of recurrent skin infections involves a systematic approach. These infections can be due to various underlying factors, and identifying the root cause is crucial for effective management and prevention.
Ask about:
Frequency and location of infections
Type of infection (boils, abscesses, cellulitis, fungal, etc.)
Hygiene practices
Close contacts with similar infections
Underlying chronic diseases (especially diabetes, HIV, malignancy)
Skin conditions (eczema, psoriasis, acne)
Medications, including immunosuppressants or steroids
Occupational exposure or sports involvement (e.g., wrestling, healthcare)
Look for:
Distribution pattern (localized vs. generalized)
Signs of chronic skin conditions
Signs of systemic illness (weight loss, lymphadenopathy)
Presence of foreign bodies or wounds
Perform culture and sensitivity testing:
Swab purulent lesions, aspirate abscesses, or biopsy chronic lesions
Rule out MRSA, fungal, or atypical mycobacteria
If fungal, do KOH prep or fungal culture
Consider PCR for certain pathogens (e.g., herpes simplex)
Check for predisposing systemic conditions:
Diabetes mellitus (check fasting glucose or HbA1c)
CBC with differential (check for neutropenia or lymphopenia)
HIV test if indicated
Immunoglobulin levels (IgG, IgA, IgM) if suspect immunodeficiency
Consider neutrophil function tests for rare cases (e.g., chronic granulomatous disease in children)
Zinc, iron, or protein deficiency can impair skin integrity and immunity
If recurrent infections occur over skin with dermatitis or other pathology, a dermatologist can help identify:
Contact dermatitis
Seborrheic dermatitis
Fungal superinfection
Crowded living conditions
Shared towels, razors
Poor wound care
Use of IV drugs or tattoos
Pets (for zoonotic fungal infections)
If the infection is specifically recurrent furunculosis:
Consider chronic nasal carriage of Staph aureus – do nasal swabs
Family screening may be needed
Mupirocin nasal ointment and chlorhexidine body wash may help eradicate colonization
Chronic granulomatous disease (CGD)
Hyper-IgE syndrome (Job's syndrome)
Severe Combined Immunodeficiency (SCID) – in infants
Take a thorough history and exam
Culture the lesion
Check bloodwork for diabetes, CBC, HIV
Assess immune status if recurrent/severe
Evaluate skin conditions
Investigate environmental and personal hygiene factors
Would you like a flowchart or checklist to guide evaluation in clinical practice?
Determining the cause of recurrent infections involves a systematic approach that includes clinical history, physical examination, laboratory testing, imaging, and sometimes referral to a specialist.
Type of infections: Skin, respiratory, urinary, gastrointestinal, etc.
Frequency and duration: How often and how long they last.
Severity: Mild or requiring hospitalization/IV antibiotics.
Location: Same site or multiple different sites.
Response to treatment: Partial, complete, or resistant to antibiotics.
Family history: Immune deficiencies or autoimmune diseases.
Environmental exposure: Travel, pets, work, daycare, etc.
Medications: Immunosuppressants, steroids, chemotherapy.
Vaccination history: Especially pneumococcus, influenza, etc.
Look for signs of chronic illness, lymphadenopathy, organomegaly.
Examine affected areas (e.g., sinuses, lungs, skin, urinary tract).
Complete blood count (CBC) with differential: Look for leukopenia or neutropenia.
Immunoglobulin levels (IgG, IgA, IgM, sometimes IgE).
Lymphocyte subsets (T cells, B cells, NK cells).
Complement levels (CH50, C3, C4).
Neutrophil function tests (e.g., nitroblue tetrazolium test or oxidative burst).
HIV testing (if risk factors or unexplained immunosuppression).
Diabetes screen: Elevated glucose can predispose to infections.
Cultures of infected sites (blood, urine, sputum, wound, etc.).
Identify organisms: Recurrent infections with the same organism vs. different ones.
Look for antibiotic resistance patterns.
CT or MRI: Evaluate for chronic infection or anatomical defects (e.g., sinus CT, chest CT, abdominal imaging).
Ultrasound: For abscesses, urinary tract abnormalities.
Sweat chloride test or genetic testing for cystic fibrosis.
Bronchoscopy: For recurrent pneumonia or unexplained cough.
Urinary tract imaging: For recurrent UTIs.
Bone marrow biopsy: If hematologic malignancy is suspected.
Immunologist: For suspected primary or secondary immunodeficiencies.
Infectious disease specialist: For difficult-to-diagnose or manage infections.
Endocrinologist: For metabolic disorders like diabetes.
Anatomic defects (e.g., sinus blockage, vesicoureteral reflux)
Immunodeficiencies:
Primary (genetic, e.g., CVID, X-linked agammaglobulinemia)
Secondary (HIV, chemotherapy, immunosuppressants, diabetes)
Chronic diseases (e.g., diabetes, malignancy)
Environmental/behavioral factors (e.g., poor hygiene, overcrowding)
If you’d like, you can tell me more about the type of infections or symptoms you’re referring to, and I can help outline a more tailored diagnostic approach.
Differential Diagnosis
Immunodeficiency Disorders:
Autoimmune Disorders:
Chronic Medical Conditions:
Hematologic Disorders:
Granulomatous Diseases:
Allergic and Asthma Conditions:
Underlying Anatomical Abnormalities:
Medications and Treatments:
Environmental Exposures:
Psychosocial Factors:
Underlying Viral Infections:
Underlying Bacterial Infections:
Underlying Fungal Infections:
Autoinflammatory Syndromes:
Gastrointestinal Disorders:
Next Pivotal Assessment