Understanding SPT in Medical Context
SPT most commonly refers to skin prick testing in allergy diagnosis, but can also refer to suprapubic tube placement in urologic care. The meaning depends entirely on the clinical context in which it is used.
Skin Prick Testing (SPT)
Skin prick testing is a widely used diagnostic procedure in allergy medicine:
- Definition: A procedure that introduces small amounts of suspected allergens into the skin surface to detect IgE-mediated allergic reactions 1, 2
- Purpose: To identify specific foods, pollens, or other substances that may provoke IgE-mediated allergic reactions 1
Procedure Details:
- Performed by placing a drop of allergen extract on the skin and pricking/puncturing the skin surface
- A positive reaction typically produces a wheal ≥3mm larger than the negative control within 15-20 minutes 1, 2
- Tests should be performed by trained healthcare professionals in settings where anaphylactic reactions can be treated 2
Clinical Significance:
- High sensitivity but low specificity and positive predictive value compared to oral food challenges 1
- A positive test indicates sensitization but must be correlated with clinical symptoms to diagnose true allergy 2
- Negative SPTs have high negative predictive value, making them valuable for ruling out allergies 1
Important Considerations:
- Patients should discontinue antihistamines before testing (short-acting: 24 hours; long-acting: 3 weeks) 2
- Emergency medications should be available during testing due to small risk (0.12%) of systemic reactions 2
- Higher risk in patients <1 year old, those with active eczema, and females 2
Suprapubic Tube (SPT)
In urologic care, SPT refers to a suprapubic catheter:
- Definition: A catheter inserted through the abdominal wall directly into the bladder to drain urine 1
- Purpose: To provide urinary drainage when urethral catheterization is contraindicated, ineffective, or undesired 1
Clinical Applications:
- Preferred method for chronic indwelling catheterization compared to urethral catheters 1
- Indicated in patients with pelvic fracture urethral injuries (PFUI) 1
- Used when oral medications or minimally invasive procedures for overactive bladder are ineffective 1
Advantages over Urethral Catheters:
- Reduced likelihood of urethral damage and trauma 1
- Allows maintenance of sexual activity 1
- Avoids urethral discomfort associated with urethral catheters 1
Potential Complications:
- Bowel perforation or vascular injury during placement 1
- Development of granulation tissue, bleeding, catheter site erosion 1
- Loss of access during catheter changes 1
Other Less Common Meanings of SPT
In specific contexts, SPT may also refer to:
- Solid-pseudopapillary tumor (rare pancreatic neoplasm) 3, 4
- Sound production treatment (therapy for apraxia of speech) 5
- Supportive periodontal therapy (maintenance therapy after periodontal treatment) 6
- Strip patch test (dermatological testing procedure) 7
When encountering the abbreviation SPT in clinical documentation, always consider the medical specialty and context to determine the intended meaning.