What are some of the symptoms of a possible immune deficiency?

What are some of the symptoms of a possible immune deficiency and how can it be related to or differentiated from allergies?

Immune deficiency is a chronic illness that causes infections that don't clear up or infections that keep coming back (or both). The illness can cause problems of diarrhoea, skin rashes or fevers. Children with immune deficiency may not grow at the expected rates for their ages. Allergies may also show up in a variety of ways, including skin rashes, constant runny nose, dark circles around the eyes or teary eyes, or breathing problems like a constant cough or wheezing. Conditions like allergies, asthma or eczema often run in families. A GP should examine any child who has health problems that don't seem to go away or that don't seem to respond to treatment. Ideally, the doctor will be familiar with the child, but, in any case, parents can help the doctor with as much information as possible on their child's history and health. To find out what is going on, your child will need an examination and probably some laboratory tests.