Sickling Test

A sickling test is very commonly performed in newborns soon after birth for the early diagnosis of SCD. The test can also be done on adults or older children who present the following symptoms of SCD:

• Anaemia
• Persistent tiredness
• Paleness
• Shortness of breath
• Yellow eyes 
• Swelling of the hands and feet
• Frequent infections 
• Delayed body growth
• Vision problems

Furthermore, a sickling test helps determines the presence of sickle cell trait, ie, to know if the individual is a genetic carrier of SCD. Such individuals may have no symptoms but can pass the disease on to their offsprings.

No special preparations are needed for this test. However, it is important to note that undergoing this test within 90 days of having received a blood transfusion can give inaccurate test results. 

Therefore, you must inform your doctor about any recent blood transfusions to avoid false results. 

For this test, a blood sample is collected as mentioned below:

• A lab technician will wrap an elastic band around your upper arm to stop the flow of blood. This will make the veins below the band larger to ensure easy insertion of a needle
• He/she will clean the site of collection with alcohol to sanitise the area and insert a needle in a vein
• Next, a tube will be attached to the needle to collect the blood sample, and once enough blood is collected, the band will be removed from your arm
• The technician will then place cotton over the needle site and apply pressure on the site to stop bleeding
• Finally, a bandage will be placed on the injection site to prevent infection

A feeling of tightness is experienced when the band is wrapped around the upper arm. Few individuals report no pain from the needle, and some may feel a quick sting or pinch.

Some risks associated with this test are:

• Difficulty in obtaining the sample
• Excessive bleeding at the site from where the blood is drawn
• Fainting 
• Haematoma (accumulation of blood under the skin)
• Infection at the site where the needle is inserted

However, these risks can easily be reduced when proper precautionary measures are taken

• A normal result would be called a negative result. This means that you have normal haemoglobin. However, a positive result would indicate that you have  SCD or the sickle cell trait. 
• If the test results are positive, the doctor may ask you to get another test called haemoglobin electrophoresis, which will help in determining the exact condition.

Disclaimer: All results must be clinically correlated with the patient’s complaints to make a complete and accurate diagnosis. The above information is provided from a purely educational point of view and is in no way a substitute for medical advice by a qualified doctor.