Normal frequency of illnesses in children
The frequency of ARVI in a child depends directly on their environment and age. On average, a healthy child has 6–8 episodes of acute respiratory infections per year. Children who have recently started attending group childcare (kindergarten, school) can get sick up to 12 times a year or more, which is not considered pathological.
Parents often overestimate this figure for several reasons:
- counting mild episodes — short-term rhinitis, sore throat;
- confusing infectious and allergic rhinitis;
- failing to account for the fact that ARVI can last up to 3 weeks with residual cough and runny nose;
- treating every residual symptom as a new illness.
If a child does not attend group childcare but gets sick often, the source of infection is usually siblings who bring viruses home from kindergarten or school.
Why a child gets sick often
The main reason for frequent ARVI is the immature immune system encountering a large number of new antigens. Only over 200 types of respiratory viruses are known, and it takes time for a child to build immunological memory — sometimes two to three years of active social contact.
Frequent colds in a child attending kindergarten are not a sign of a "weak immune system," but a natural stage of its maturation. The immune system is a complex mechanism, and its true failures (immunodeficiencies) present in fundamentally different ways.
Immunodeficiencies and "immunomodulators"
True immunodeficiencies are severe conditions that require treatment with potent medications under strict medical supervision. Such medications often cause severe side effects and are available by prescription only.
Practical guideline: if a "boost immunity" remedy is recommended without a prescription and sold over-the-counter, it is highly likely to lack proven efficacy and does not affect immune function.
Two groups of immune disorders
Immune problems are conventionally divided into two major groups:
- Insufficient activity of the immune system — immunodeficiencies manifested by frequent and severe infections.
- Excessive activity of the immune system — autoimmune and immune-inflammatory diseases.
These groups may be interrelated: a deficiency in one arm of immunity is often accompanied by hyperactivity of another.
Warning signs of immunodeficiency
The following criteria warrant a comprehensive evaluation:
- Family history: cases of immunodeficiency in relatives or the death of a child in the family from a severe infection is an indication for a genetic consultation.
- Inadequate physical development — failure to gain weight and height (failure to thrive).
- Frequent bacterial infections: ≥4 suppurative otitis media episodes per year; ≥2 bacterial sinusitis episodes per year; ≥2 pneumonia episodes per year; need for antibacterial therapy for more than 2 months without effect; need for intravenous antibiotics; ≥2 generalized infections (e.g., sepsis); recurrent abscesses of the skin, soft tissues, and internal organs, including lung abscess.
- Infections with atypical or opportunistic pathogens.
- Complications after administration of live vaccines, in particular generalized BCG infection after vaccination in the maternity hospital.
- Prolonged recurrent candidiasis of the skin and mucous membranes, especially in children over 1 year of age.
- Persistent enlargement of immune organs — lymph nodes, liver, spleen (taking into account possible transient enlargement in infectious mononucleosis and other infections).
- Prolonged diarrhea, frequent intestinal infections, inflammatory bowel disease unresponsive to therapy.
- Severe skin manifestations: refractory atopic dermatitis, recurrent urticaria unresponsive to antihistamines and glucocorticosteroids, unexplained edema.
- Autoimmune diseases and their combinations, including endocrinopathies; a typical example is systemic lupus erythematosus.
The presence of two or more of the listed signs is grounds for evaluation to rule out primary immunodeficiency.
Key points
- Normal for a child: 6–8 ARVI per year; for those newly entering group childcare: up to 12 and more.
- ARVI can last up to 3 weeks; residual symptoms are not considered a new episode.
- Frequent colds in a child in kindergarten are not immunodeficiency, but rather immune system adaptation to over 200 types of viruses.
- Over-the-counter "immunomodulators" do not affect immune function.
- True immunodeficiencies manifest as severe bacterial, fungal, and opportunistic infections, rather than frequent ARVI.
- Key red flags: ≥2 pneumonias or ≥4 ear infections per year, abscesses, BCGitis, recurrent candidiasis, developmental delay.
- A family history of a child dying from infection requires a genetics consultation.
- The presence of ≥2 warning signs is an indication for an immunological evaluation.