Environmental Allergy Treatment in San Francisco, CA 

Environmental allergies are among the most common chronic health conditions in the United States and living in the San Francisco Bay Area comes with its own unique allergy challenges. The mild, damp coastal climate supports year-round mold growth. Cypress, juniper, oak, and olive trees pollinate for months at a stretch. And climate change has extended the Bay Area’s pollen and mold season by eight to nine weeks compared to two decades ago. 

At SH Allergy, Asthma & Immunology, our board-certified allergists and immunologists specialize in identifying exactly what triggers your symptoms and in treating the underlying cause, not just masking it. Whether you have been sneezing through every spring for years, or you have recently moved to San Francisco and developed new symptoms you have never had before, we are here to help. 

What Are Environmental Allergies? 

Environmental allergies also called allergic rhinitis, hay fever, or aeroallergies occur when the immune system mistakenly identifies a harmless airborne substance as a threat. In response, it produces IgE antibodies, triggering the release of histamine and other inflammatory chemicals that cause the symptoms you feel. 

Unlike food or medication allergies, which are triggered by ingesting a substance, environmental allergies are caused by airborne particles you breathe in or that land on your eyes and skin. These allergens can come from outdoor sources like pollen and mold, or indoor sources like dust mites, pet dander, and cockroach proteins. 

When hay fever, allergic rhinitis (nasal inflammation), and allergic conjunctivitis (eye inflammation) are caused by environmental triggers, they all share the same underlying mechanism — and they can all be accurately diagnosed and effectively managed at our clinics. 

Common Environmental Triggers in the San Francisco Bay Area 

San Francisco’s climate and urban vegetation create an unusually complex allergy environment. Newcomers to the Bay Area frequently develop new sensitivities within one to three years of arriving particularly to cypress, olive, and birch pollen, and to the persistent mold associated with the city’s coastal fog. 

Winter / Early Spring (January – March) 

Cypress, juniper, and cedar tree pollen among the earliest and most significant local triggers. Mountain cedar from inland areas can also affect Bay Area residents on high-wind days 

Spring (March – May) 

Oak, olive, and birch tree pollen peak. Grass pollen begins (Timothy, ryegrass, Bermuda). This is the highest-burden season for most Bay Area allergy patients 

Summer (June – August) 

Grass pollen continues through July. Outdoor mold from decaying vegetation in parks increases as the dry season progresses 

Fall (September – November) 

Chinese elm provides a second tree pollen wave. The first significant rain after the dry summer triggers a large mold spore release as dormant mold reactivates in soil, leaves, and organic matter 

Year-round 

Weed pollen (nettle, sagebrush, dock) at low to moderate levels; indoor mold in fog-exposed homes persistent throughout the year 

Symptoms of Environmental Allergies 

Diagnosis: How Environmental Allergies Are Tested 

Skin Prick Testing 

Skin prick testing (also called scratch testing) is the most commonly used and clinically validated method for identifying environmental allergens. Small amounts of allergen extracts including local tree pollens, grasses, weeds, molds, dust mites, and pet danders are introduced to the surface of the skin on your forearm or back using a small lancet. 

After 15 to 20 minutes, the skin is assessed for a reaction. A raised wheal (similar to a mosquito bite) at a test site confirms sensitization to that allergen. The test is safe and well-tolerated most patients describe only mild, brief itching at positive sites. 

Intradermal Testing 

If skin prick testing is inconclusive for a specific allergen, intradermal testing may be performed. A small amount of allergen is injected just below the skin surface. Intradermal testing is more sensitive than skin prick testing and is commonly used when there is strong clinical suspicion of a specific allergy but a negative or borderline skin prick result. 

Blood Testing (Specific IgE) 

Blood-based specific IgE testing (sometimes called RAST or ImmunoCAP testing) measures the level of allergy antibodies in the blood for specific allergens. It does not require stopping antihistamines and can be performed when skin testing is not possible for example, in patients with extensive eczema, those on medications that cannot be stopped, or young children for whom skin testing may not be appropriate. 

Blood testing and skin testing are complementary tools. Your allergist will recommend the most appropriate method based on your clinical history. 

Treatment Options for Environmental Allergies 

Effective management of environmental allergies typically involves a combination of three approaches: reducing your exposure to allergens, controlling symptoms with medication, and for long-term relief addressing the underlying immune response through immunotherapy. 

Allergen Avoidance 

Reducing your exposure to identified triggers is the first line of management. Your allergist will provide personalized avoidance guidance based on your specific test results. Common strategies include: 

• Checking local pollen counts and limiting time outdoors on high-count days, keeping windows closed during peak pollen seasons, and showering after outdoor activities to remove pollen from skin and hair 

• Using allergen-impermeable mattress and pillow covers for dust mite allergy; washing bedding weekly in hot water 

• Using a HEPA air purifier in sleeping and living areas; replacing HVAC filters regularly 

• Addressing indoor mold through proper ventilation, dehumidification, and remediation of visible growth 

• For pet dander: keeping pets out of the bedroom; regular bathing; HEPA vacuuming and air filtration 

Medication Management 

Medications can significantly reduce symptoms and improve quality of life, particularly during high-exposure periods. Your allergist will recommend the most appropriate options based on the type and severity of your symptoms. 

Allergen Immunotherapy 

Allergen immunotherapy is the only treatment option that targets the underlying immune mechanism of environmental allergies — not just the symptoms. By gradually exposing the immune system to increasing amounts of the specific allergens causing your symptoms, immunotherapy retrains it to tolerate those substances rather than react to them. 

Unlike antihistamines or nasal sprays, which must be taken continuously to maintain symptom control, immunotherapy can produce lasting benefits that persist for years after treatment is completed. Studies have also shown that immunotherapy can prevent the development of new allergies and reduce the progression of allergic rhinitis to asthma.