1) Doctor 2) Expert for pollen counters 3) Medico 4) Physician 5) Scratch-test specialist 6) Specialist of a sort 
Synonym for immunologist ... <specialist> A specialist practiced in the treatment of allergic disease and those disease processes that involve dysfunction of the immune system. ... (27 Sep 1997) ... 
(al´әr-jist) a physician specializing in the diagnosis and treatment of allergic conditions.
Type: Term Pronunciation: al′er-jist Definitions: 1. One who specializes in the treatment of allergies.
[n] - a physician skilled in the diagnosis and treatment of allergies
noun a physician skilled in the diagnosis and treatment of allergies
a physician specializing in the diagnosis and treatment of allergies.