Python: Having issue with printing out only 1 line in a for loop

So my code outputs the value if the keys are found inside a dictionary using a userInput. I want to print out a message saying "Disease name does not exist" if the userInput is not found in the keys of the dictionary. I can get it to work, however, it goes through the wholeee list and repeats "Disease does not exist" for every line of the text.txt

I can't figure out how to make it just print once. Here is my code:

# Complete this function to meet its specifications.
# Begin with an empty dictionary, fill it, and return it.
def disease_to_code_dictionary(  ) :
    """ Function returns a dictionary with disease names as keys and
      ICD 10 codes as values. """

    diseases = {}

    infile = open("ICD10.txt","r")
    header_row = infile.readline() # skip the header row

    for line in infile :

        cells = line.split("\t") # split by the tab character

        if len(cells) >= 2 : # only if the line had a tab
            code = cells[0]
            disease = cells[1]
            disease = disease.lower() # lowercase
            disease = disease.replace("\"","") # remove all double quotes

            diseases[disease] = code
                
    infile.close()
    
    return diseases


# Complete this function to meet its specifications.
# The program should give the code if the disease name exists
# otherwise say "Disease name does not exist.".
def query_disease_to_code() :
    """ Interactive function to query code from disease name. """
    d = disease_to_code_dictionary() # disease to code dictionary

    query = input("Give disease name (q to quit): ")

    while query != "q" :
        query = query.lower() # lowercase
        # complete here
        for key, value in d.items():
            if query in key:
                print(value)
            else:
                print("Disease name does not exist.")
        
        query = input("Give disease name (q to quit): ")
         
    
query_disease_to_code()