Désirée Larenas-Linnemann, MD, from Hospital Médica Sur

Désirée Larenas-Linnemann, MD

Barriers to Using SLIT, With Désirée Larenas-Linnemann, MD

2026 American Academy of Allergy, Asthma & Immunology

, from Hospital Médica Sur, shared persistent real‑world barriers to broader adoption of 

 in the United States. Although SLIT can offer a home‑based alternative to injections, financial and practical hurdles continue to limit its uptake.

“It’s only one allergen that you can give in a tablet,” Larenas-Linnemann said. “If you want to do 2 allergens, you have to give 2 tablets, which doubles the cost. Most tablets are not covered by insurance.”

She further emphasized the complexity of prescribing tablets for allergic asthma, as not all formulations have FDA approval for this indication. However, since many patients also have concomitant allergic rhinitis, clinicians often navigate this off-label use.

Adherence is another critical factor. Larenas-Linnemann described wide variability among patients, observing that while some strictly follow daily dosing, others stretch vials beyond recommended intervals, undermining therapeutic effectiveness.

“If you really want to have good effects, you need to have your monthly dose,” she said. “You need to have your daily dose, ideally, with the tablets.”

Emerging research on multi-allergen SLIT, particularly in liquid form, may expand treatment options, though evidence remains limited. Larenas-Linnemann said it could be possible to use 2 tablets for multi-allergen therapy, but evidence is scarce. European guidelines suggest a 30-minute interval, but this is based on a single study, and the effect of administering 2 tablets simultaneously remains unknown.

“It's a recommendation without solid evidence behind it,” Larenas-Linnemann said.

When it comes to multi‑allergen SLIT, Larenas‑Linnemann emphasized careful patient selection. Typical combinations might include grass pollen, tree pollen, cat dander, and house dust mite. Clinicians must ensure the patient is clinically reactive to these allergens, as positive skin tests alone do not always reflect current symptomatic allergy. For example, patients may test positive for mold exposure they encountered years ago but no longer experience symptoms in their current environment, making immunotherapy unnecessary for that allergen.

Evidence for multi‑allergen liquid SLIT remains limited but promising. Studies combining 2 allergens, such as house dust mite and grass pollen, have demonstrated efficacy over 1 to 2 years. Trials mixing 3 or 4 allergens show weaker but still observable responses, and even studies attempting 10-allergen combinations suggest a signal of benefit when focusing on relevant allergens. Larenas‑Linnemann noted that statistical significance may be limited by small sample sizes.

In her practice, she limits multi‑allergen therapy to no more than four allergens, using liquid formulations with high concentrations

to maximize the potential therapeutic effect. The goal is to deliver the strongest possible dose for each relevant allergen, balancing efficacy with safety.

Larenas-Linnemann has no relevant disclosures.

Larenas-Linnemann, D. What Should You Know About SLIT in 2026? Session presented at the American Academy of Allergy, Asthma, & Immunology (AAAAI) in Philadelphia on February 28, 2026.

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High costs, limited insurance coverage, and adherence challenges remain key barriers to broader SLIT use in the US, Larenas-Linnemann says in an interview at AAAAI 2026.

Sublingual Immunotherapy for Allergy in 2026, With Désirée Larenas-Linnemann, MD

2026 American Academy of Allergy, Asthma & Immunology (AAAAI) annual meeting

 in Philadelphia, Désirée Larenas-Linnemann, MD, from Hospital Médica Sur, presented “What Should You Know About SLIT in 2026?”

 fits into the evolving allergen immunotherapy landscape.

Allergen immunotherapy has long been a cornerstone of treatment for allergic diseases because it targets the underlying immune dysregulation rather than simply controlling symptoms. The therapy has been used clinically for more than a century, beginning with early allergy injections administered in 1911.

“Allergen immunotherapy… really goes to the cause of allergic diseases…particularly [in] allergic rhinitis, allergic conjunctivitis, allergic asthma,” Larenas-Linnemann told

 during the meeting. “[The therapy attacks] this altered immune system and brings it back on its track.”

Traditionally, allergen immunotherapy has been administered via subcutaneous injections given in a clinical setting, which are effective but require frequent office visits and carry a small risk of systemic allergic reactions. These logistical and safety considerations have contributed to growing interest in sublingual allergen immunotherapy. Larenas-Linnemann said strong evidence on sublingual immunotherapy was published in 2006.

Today, several sublingual immunotherapy tablets are available for specific allergens, including grass pollen, ragweed, and house dust mite. These products are approved in the United States for the treatment of allergic rhinitis and allergic conjunctivitis, providing patients with a home-based treatment option that avoids injections.

According to Larenas-Linnemann, sublingual therapy can also play an important role in managing certain cases of asthma, particularly allergic asthma, which remains common among pediatric and adult patients. Safety considerations are particularly relevant for patients with asthma undergoing injection immunotherapy, since poorly controlled disease can increase the risk of adverse reactions. For this reason, clinicians often postpone subcutaneous injections if a patient is experiencing an asthma flare or has recently required emergency care.

Allergen immunotherapy is also recognized for its disease-modifying potential. Unlike standard medications, which typically relieve symptoms only while they are being used, immunotherapy can produce durable clinical benefits after treatment is discontinued. Evidence from clinical trials suggests that ≥ 3 years of treatment with high-dose sublingual immunotherapy is necessary to achieve sustained effects.

 For example, studies of grass pollen sublingual tablets have shown that patients who complete 3 years of therapy maintain symptom improvement for ≥ 2 additional years after stopping treatment.

Clinical guidance for allergen immunotherapy is also evolving. Updated practice parameters for allergen immunotherapy are currently in development and are expected to include expanded guidance on sublingual therapy. Larenas-Linnemann said the guideline revision process has taken > 2 years, with the first part written in July 2023. The forthcoming update is expected to provide clearer recommendations for clinicians on how to incorporate sublingual immunotherapy into routine allergy care.

“This has been a long journey,” she said. “[There have been] a lot of comments [like] ‘push it there! No, [let’s] do [a] different order! No, no, this is not true!’ and ‘where’s the evidence? Now, is there new evidence? So, we really hope to have them out for public comments… in the next 2 [to] 3 months. [It] definitely [has] to be published [in] the second half of this year, hopefully third quarter.”

What Should You Know About SLIT in 2026? Session presented at the American Academy of Allergy, Asthma, & Immunology (AAAAI) in Philadelphia on February 28, 2026.

Persaud Y, Memon RJ, Savliwala MN. Allergy Immunotherapy. [Updated 2023 May 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan-. Available from: 

https://www.ncbi.nlm.nih.gov/books/NBK535367/

AllergenuityHealth. Do Sublingual Immunotherapy (SLIT allergy drops) results persist after treatment is stopped? - Allergenuity Health Associates. Allergenuity Health Associates. Published July 5, 2018. Accessed March 9, 2026. 

https://allergenuityhealth.com/faq-items/do-sublingual-immunotherapy-slit-allergy-drops-results-persist-after-treatment-is-stopped/

Scadding GW, Calderon MA, Shamji MH, et al. Effect of 2 Years of Treatment With Sublingual Grass Pollen Immunotherapy on Nasal Response to Allergen Challenge at 3 Years Among Patients With Moderate to Severe Seasonal Allergic Rhinitis: The GRASS Randomized Clinical Trial. 

At AAAAI 2026, Larenas-Linnemann discusses evidence, safety, and long-term benefits of sublingual immunotherapy for allergic rhinitis and asthma.

Désirée Larenas-Linnemann, MD

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