Delayed Type Hypersensitivity Skin Testing Flashcards
What is DTH?
It is used to evaluate the functionality of the Immune system
On the Gell and Combs scale, DTH is what type?
Type IV
It is the reduction or lack of an immune response to a specific antigen
Anergy
The patient does not respond to any of the antigens
Anergic
what is the procedure used to determine a persons immune response?
Anergy Panel
What are the indications for DTH?
- Evaluate the immunity of patients with possible immune deficiencies
- Assess the immuno-competency of malnourished patients
- To assess patients for possible chemotherapy
- HIV staging
- Pre and Post surgery patients to assess level of infection risk
When administering DTH what is the first strength used?
PPD - 5 TU
Candida - 20 PNU
When administering DTH what is the second strength used?
PPD - 5 TU
Candida - 200 PNU
When do the reactions for DTH start?
24 hours
When do the reactions for DTH peak?
48 hours
When do the reactions for DTH subside?
72 hours
What dose is administered for all DTH antigens?
0.1 ml
When screening a patient for DTH placement what questions are you going to ask?
- Have you ever had a past positive reaction
- Is there a history of BCG Vaccine
- Can the patient return in 48-72 hours
- Are they taking any steroids or radiation therapy
- any live vaccines in the past 28 days
What patient instructions are given after the placement of DTH?
Absolutely NO:
- Scratching/ Rubbing/ Agitating
- Lotions/ Soaps/ Oils
- Colognes/ perfumes
- Bandages
All readings for DTH are measured how?
Induration X Induration
When reading DTH what is considered a positive reaction?
5mm or greater
When reading DTH what is the one thing that must be done regardless if there is visible reaction?
Palpation
What would cause a false negative reaction for DTH testing?
- Too old/young
- No Prior Exposure
- Active Viral Infection
- Solutions are Weak or Out-dated
- Improper Placement
- Recent Live Viruses
What would cause a false positive reaction for DTH testing ?
- Scratching/ Rubbing/ Agitating
- Lotions/ Soaps/ Oils
- Colognes/ perfumes
- wrong diluent used when preparing the antigen
Healthy people will normally react to how many of the DTH antigens?
At least one of the two
Through out your body you have a large amount of __________ that are able to recognize many different antigen in your body
T-Cells
When placing DTH antigens what is the minimum distance they should be placed apart from each other
at least 5 cm
