Skin Prick Test-need help understanding

[cobbiemommy]

DS, had a skin prick test at the doctor's office on Mon. On the left arm, he received a tiny prick and the tuberculin antigen. On the right arm he received a tiny prick of candida in the upper half of his forearm and diphtheria toxin on the lower half of his forearm. I hope that is the right name for the diphtheria/tetanus antigen. After 48 hours, I had to document the size and color of any reaction from the antigens.

 

 

There was no reaction to the TB antigen and the reaction to the candida was smaller than 2 mm and no color. The diphtheria/tetanus was mildly pink and about 2 mm in size.

 

Does anyone know how to interpret these results? I believe it means that he makes no antibody response, but I'm not sure.

 

Thanks,

Cobbie

[junkyardjean]

I don't have any answers, but wanted to say I'm glad you are asking! They have decided to send dd for this and I have no idea what to expect...

 

Will "intolerances" will captured, or just "allergies"? I use quotation marks as I've benn scolded by past drs that intolerances are nothing - but for her, they are everything!

[cobbiemommy]

This was not an allergy test. It was supposed to measure an immune reaction, or lack thereof. I know that it is supposed to measure immune reaction against two common known antigens-candida and the tetanus. I will keep looking for answers as well.

Edited August 16, 2013 by cobbiemommy

[911RN]

The tuberculin skin test is to test for exposure to TB- it is to see if one has had unknown exposure to TB. You can be "exposed" by someone coughing in a grocery store line. Does not mean you have TB as a disease. One gets the skin test then waits 48 hours and it is "read" for results. It is deemed positive-meaning you have been 'exposed' to TB if there is redness and induration- usually 10 mm or more. Induration is a hard, swollen red area. Hard to miss once you have seen a "positive" TB skin test. If a skin test come back positive then you never receive skin test for TB again- will always be positive. Usually they follow positive skin test with chest xray to see if there is any evidence of TB as a disease. If not, then there is usually no worry. Over half of health care workers will sero- convert to TB positive skin tests although they never have evidence of TB as a disease. TB is not a disease we are immunized against- in other words, you would want a lack thereof response.

 

It does not sound as if the TB skin test on your child was positive. Your description sounded negative to me. I have never seen the Candida or diptheria/tetanus 'skin test' done so I am not able to speak to that.

 

These are typically read by nurses or MD's- I am surprised they would allow you to interpret it yourself and not come back to have it checked. Health care workers get TB tested every year. Our hospital is so strict- if you do not have it read and signed within the 48-72 hour window (by another nurse) as designated on the form then they make us repeat it.

[LNN]

never mind - 911RN's answer is much clearer than mine was.

Edited August 16, 2013 by LLM

[Mayzoo]

Information on reading the candida:

 

"Candin® Skin Test Antigen

Candin® is the only FDA licensed DTH skin test antigen made from Candida albicans. It is potency standardized by DTH skin testing in humans. The product is indicated in the assessment of immune responsiveness in clinical situations involving the cellular immune system. Intact cell-mediated immunity (CMI) requires a complex interaction between lymphocytes, macrophages and cytokines. Various immune disorders and disease processes can alter the CMI response. These include congenital immunodeficiencies, acquired immunodeficiencies, cancer, malnutrition and viral and fungal diseases. A positive DTH response to Candin® indicates that the CMI is functioning properly. Candin® is frequently used as a control for tuberculin skin testing to rule out anergy as a possible factor in persons who are skin-test negative to tuberculin. For full prescribing information see insert. " http://www.allermed.com/candin/

 

http://www.healthcentral.com/allergy/tests-6229-146.html

 

http://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=634f5c5e-8625-4aa3-baa6-8ab82d5c1afa

 

Information on reading the diptheria/tetnus:

 

http://www.cdc.gov/diphtheria/downloads/skintest-guide.pdf

Edited August 16, 2013 by Mayzoo