Hi My 19th Month Old Has A Prominent Clavical On

Hi my 19th month old has a prominent clavical on the right hand side. It doesn't seem to cause him any pain and feels like a hard but it's become prominent in the last few months.
We are currently waiting on an ultrasound, however, we may have to wait another few weeks.
He has lost weight, he is sleepin more than normal and has bad eczema (including his scalp)
The skin is not red around clavicle.
He is currently taking antibiotics for inflamed ear and tonsils.
Can you please advise