11.2 Allergic Rhinitis, Urticaria & Immunodeficiency Clues
Key Takeaways
- Intranasal corticosteroids are first-line for persistent allergic rhinitis; add second-generation oral antihistamines and allergen avoidance. Do not use oral decongestants as routine therapy in young children.
- Acute urticaria lasts fewer than 6 weeks and is often viral or idiopathic; chronic urticaria lasts 6 weeks or longer. Respiratory, cardiovascular, or severe gastrointestinal signs mean treat as anaphylaxis, not "just hives."
- The atopic march (eczema → food allergy → allergic rhinitis → asthma) is a pattern to watch, not a destiny — control eczema and introduce peanut on time.
- Primary immunodeficiency red flags include recurrent deep abscesses, two or more pneumonias, failure to thrive, persistent thrush, need for intravenous antibiotics, and a positive family history — refer immunology and use live-vaccine caution.
- Transient hypogammaglobulinemia of infancy is not SCID or X-linked agammaglobulinemia. Frequent viral upper respiratory infections with normal growth and recovery between illnesses are not immunodeficiency.
After food anaphylaxis, the rest of clinical category #3 is the daily allergy work of primary care: itchy noses, hives, the atopic march, and the uncommon child whose "infections" are not daycare rhinovirus. Domain III wants a controller that actually works for persistent allergic rhinitis and a referral trigger for immunodeficiency — not a decongestant syrup and not a diagnosis of "weak immunity" because a toddler had eight colds.
Allergic rhinitis: controller first, not a decongestant
Allergic rhinitis (AR) is IgE-mediated inflammation of the nasal mucosa after allergen exposure. Seasonal disease tracks pollens. Perennial disease tracks dust mite, pet dander, cockroach, and indoor molds. Many children have both.
Exam clues: allergic salute and a transverse nasal crease, allergic shiners, Dennie–Morgan folds, pale boggy turbinates, clear rhinorrhea, nasal itching, and posterior pharyngeal cobblestoning. Mouth-breathing and snoring overlap with adenoidal hypertrophy; AR can worsen sleep-disordered breathing but is not the only explanation for a blocked nose.
Intranasal corticosteroid (INCS) is first-line for persistent symptoms that impair sleep, school, or sport. Fluticasone, mometasone, budesonide, and similar agents reduce sneezing, itching, rhinorrhea, and congestion better than oral antihistamines for nasal blockage. Teach technique: prime the bottle, head slightly down, aim the spray outward toward the lateral nasal wall — not onto the septum, not a hard snort into the throat. Benefit builds over days; this is a controller, not a single-spray rescue like oxymetazoline.
Second-generation oral antihistamines (cetirizine, loratadine, fexofenadine, levocetirizine) help itch, sneeze, and rhinorrhea and are useful for intermittent symptoms or as add-on therapy. They are not interchangeable with first-generation diphenhydramine. Diphenhydramine sedates, can paradoxically agitate toddlers, and is a poor daily school controller. Do not prescribe nightly diphenhydramine as a sleep aid dressed up as allergy care.
Allergen avoidance is counseling, not an empty slogan: encase mite-impermeable covers on the pillow and mattress when mite allergy is likely; wash bedding hot; do not smoke; reduce cockroach exposure in infested housing; pet removal is the most effective pet intervention but is not always achievable — washing the animal and keeping it out of the bedroom is a lesser plan. Saline irrigation is a reasonable adjunct.
| Therapy | Role | Trap |
|---|---|---|
| Intranasal corticosteroid | First-line controller for persistent AR | Aiming at the septum, using it as a one-time rescue, or skipping it because "steroid" sounds systemic — pediatric INCS at labeled doses has minimal systemic effect |
| Second-generation oral antihistamine | Intermittent symptoms, itch, add-on | Using diphenhydramine as the daily controller |
| Allergen avoidance | Always part of the plan | Promising that a HEPA filter alone will replace the INCS |
| Oral decongestants (pseudoephedrine, phenylephrine) | Not routine in young children | Automatic cold-and-allergy syrups in toddlers — limited benefit, cardiac and behavioral adverse effects; do not use as a controller |
| Intranasal decongestant | Very short-term congestion in older children | Rebound rhinitis if used beyond about 3 days |
| Montelukast | Not first-line AR | Boxed warning for serious neuropsychiatric events — do not open with montelukast for garden-variety AR |
Do not use oral decongestants routinely in young children. FDA has warned against cough-and-cold decongestants in infants; manufacturers label many products not to use under age 4. Phenylephrine and pseudoephedrine are not a pediatric rhinitis strategy. If a stem offers "pseudoephedrine three times daily" as the controller for a 3-year-old's year-round AR, it is the wrong answer.
Refer allergy for immunotherapy when symptoms remain impairing despite INCS, antihistamine, and avoidance, and when specific IgE to a relevant allergen is documented. Immunotherapy is not the first prescription at the first seasonal sneeze.
Clinic vignette. A 9-year-old has month-after-month nasal congestion, shiners, and poor sleep. The parent has been rotating oral decongestant-antihistamine combinations. Start an INCS with technique teaching and a second-generation antihistamine if itch is prominent. Stop the decongestant as the plan.
Urticaria: acute versus chronic, and the anaphylaxis overlap
Acute urticaria lasts fewer than 6 weeks. In children it is often viral or idiopathic. Food and drug triggers matter when the history is immediate and reproducible; a hive outbreak on day 3 of a fever is usually the virus, not a new food-allergy diagnosis.
Chronic urticaria is wheals on most days for 6 weeks or longer. Most childhood chronic spontaneous urticaria is not a hidden food allergy. Do not order a 30-food IgE panel as the workup. A limited laboratory look (CBC, inflammation marker, sometimes TSH) is enough in an otherwise well child; the main therapy is a second-generation H1 antihistamine, up-titrated, not daily systemic steroids.
Anaphylaxis overlap. Urticaria plus respiratory compromise, hypotension, collapse, or severe gastrointestinal symptoms is anaphylaxis until proven otherwise — go to the 11.1 algorithm (IM epinephrine, EMS). Isolated hives with a normal respiratory exam and normal perfusion are treated as urticaria. Angioedema without urticaria is a different pathway (hereditary angioedema, ACE-inhibitor effect in rare older adolescents); it is not "give diphenhydramine and send home" if the airway is threatened.
The atopic march
Many children follow a sequence: atopic dermatitis in infancy, food allergy in infancy or toddlerhood, then allergic rhinitis and asthma in later childhood. That atopic march is a pattern, not a sentence. Controlling eczema, introducing peanut on the NIAID timetable (11.1), and treating rhinitis well are how primary care interrupts the cascade. Do not tell a family with infant eczema that asthma is inevitable. Do not skip rhinitis treatment because "it is just allergies" in a child who already wheezes.
Primary immunodeficiency: red flags, not recurrent colds
Typical daycare toddlers have many viral upper respiratory infections a year, recover between them, grow, and have normal exams. That is immunology working. Primary immunodeficiency (PID) is suggested by infections that are too frequent for the setting, too deep, too opportunistic, or too poorly cleared.
High-yield warning signs the CPNP-PC must not explain away as "daycare":
| Red flag | Why it is not a normal cold |
|---|---|
| Recurrent deep abscesses (skin, organ, or perirectal) | Suggests neutrophil or oxidative-burst defects (chronic granulomatous disease and related) |
| Two or more pneumonias | Deep end-organ bacterial disease, not rhinovirus |
| Failure to thrive | SCID and other combined defects present as growth failure plus infection |
| Persistent oral thrush or other persistent fungal disease after the newborn period, especially with treatment | T-cell dysfunction until proven otherwise |
| Need for intravenous antibiotics to clear infections | Severity, not "a long cold" |
| Family history of PID, unexplained infant deaths, or known consanguinity | Changes the pre-test probability immediately |
| Two or more months of antibiotics with little effect; two or more deep-seated infections; persistent opportunistic organisms | Same referral logic |
Refer immunology when those flags are present. Do not start empiric monthly intramuscular antibiotics in primary care as a substitute for a workup. Check whether the newborn T-cell receptor excision circle (TREC) screen was normal if you can obtain it; a missed or abnormal SCID screen is an emergency, not a well-child footnote.
Live-vaccine caution. Until a suspected combined or severe antibody deficiency is excluded, do not give live vaccines (rotavirus, MMR, varicella, LAIV). Rotavirus in undiagnosed SCID is a classic preventable disaster. Inactivated vaccines may still be indicated and sometimes extra; antibody-deficiency patients often need a specialist plan, not a catch-up-all-live-products visit.
Transient hypogammaglobulinemia versus true PID
Physiologic IgG nadir occurs in infancy as maternal antibody wanes. Transient hypogammaglobulinemia of infancy (THI) is a prolonged low IgG with normal B-cell numbers and, often, preserved vaccine antibody responses. Infections are usually mild to moderate. It resolves. It is a diagnosis of exclusion after a specialist look — not a label you apply because a 10-month-old in daycare has a runny nose.
True PID looks different:
| Condition | Distinguishing primary-care clues |
|---|---|
| SCID | Early FTT, chronic diarrhea, thrush, opportunistic infection, absent or very low T cells; emergency; no live vaccines |
| X-linked agammaglobulinemia | Boys; absent B cells and tonsils/adenoids; severe bacterial sinopulmonary and enteroviral disease after maternal IgG wanes |
| Chronic granulomatous disease | Recurrent abscesses with catalase-positive organisms; granulomas |
| 22q11.2 / DiGeorge spectrum | Cardiac anomalies, hypocalcemia, unusual ears or palate; T-cell number and function vary — live vaccines only when T-cell function is known to be adequate |
| CVID | Older child or adolescent; low IgG plus low IgA or IgM and poor vaccine responses |
THI has B cells and usually vaccine responses. X-linked agammaglobulinemia does not. SCID is a T-cell emergency. Those three are not synonyms.
Not every recurrent URI is immunodeficiency
A 3-year-old in full-time daycare who has 8–12 viral colds a year, grows on the curve, has no deep abscesses, no two pneumonias, no persistent thrush, and recovers without IV antibiotics has a normal infection burden. Treat each illness on its merits (including the AOM and sinusitis rules in 11.3). Do not start an immunodeficiency evaluation because the parent is exhausted by tissues. Do start one when the red-flag table lights up.
Exam traps. Oral decongestant as the persistent-AR controller. First-generation antihistamine as daily therapy. Food-IgE panel for chronic urticaria. Calling daycare viral URIs "immune deficiency." Giving MMR and varicella today to a toddler with FTT, thrush, and recurrent deep infections. Treating urticaria-plus-wheeze as "just hives."
INCS for persistent rhinitis, second-generation antihistamines, no routine pediatric oral decongestants, urticaria versus anaphylaxis, and a short PID red-flag list with live-vaccine caution. That is this section on the exam.
A 6-year-old has year-round nasal congestion, allergic shiners, and poor sleep from nasal blockage. There is no fever and no purulent drainage. What is the first-line pharmacologic controller?
A 3-year-old in full-time daycare has had nine viral upper respiratory infections this year, grows well, recovers between illnesses, and has never needed intravenous antibiotics. The parent asks whether the child has an immune deficiency. What is the best CPNP-PC response?
A 14-month-old has failure to thrive, persistent oral thrush after nystatin, two hospitalizations for pneumonia, and a family history of an infant sibling who died of infection. Immunizations are incomplete. What should the CPNP-PC do about live vaccines and next steps?