Allergies can get worse over time. This applies to all allergies, not just outdoor/inhalant allergies.
Avoidance is far superior to suppressing your body's immune system with medication so you can continue to eat the foods your body is trying to tell you not to eat. Also, if you take steroids and/or antihistamines all the time, then when you really need the medication for a severe reaction, they may not work as well because your body may have adapted to the medication.
In your case, there are suitable substitutes out there for both dairy and egg. Soy milk, rice milk, nut milks, oat milk all come in cartons in the health food section of many grocery stores. Egg substitutes are also available, although egg tends to hide in a lot of things without always being listed on the main ingredient label (food labeling laws require that eggs be listed in an allergy statement if there is any chance that the product could be cross-contaminated with eggs or contain a small amount of egg as part of the ingredients). You might look into Amy's Kitchen frozen meals (some large grocery stores & health food stores carry this brand) - this company offers many dairy-free options, and all of their foods are egg-free. They also have some wheat-free options.
The following links contain some additional info:
I hope this helps - take care,
Gluten & Sulfite Sensitivity, Many Food/Inhalant/Medication Allergies & Intolerances, Asthma, Gut issues (dysmotility, non-specific inflammation), UCTD (Lupus?), Osteoporosis, Anemia, T- & B-Cell Lymphopenia, malabsorption/malnutrition, Lyme Disease (Igenex Lab IgM WesternBlot positive/CDC negative), etc.
Meds: Pulmicort, Injectable Vitamin B12, Herbs, Nutritional Supplements, Homeopathy.