Diatheses in children

Exudative-catarrhal diathesis

The predisposition to allergies and infectious diseases in early childhood is largely due to the immaturity of the gastrointestinal tract. Key roles are played by low enzymatic activity and a deficiency of secretory immunoglobulin A (sIgA).

In most patients, symptoms resolve completely by two to three years of age. However, in approximately every fourth child (20–25%), these transient phenomena progress to an atopic phenotype with the development of true allergic diseases. This process often takes the form of the so-called atopic march, which is characterized by a stage-by-stage progression in the severity of the pathology:

1. Atopic dermatitis.
2. Allergic rhinitis.
3. Bronchial asthma.

Lymphatic-hypoplastic diathesis

This constitutional anomaly manifests as diffuse lymphoid hyperplasia (enlargement of the thymus and lymph nodes). The pathology is accompanied by decreased immunity, endocrine imbalance, and weak adaptive capabilities.

• Causes: genetics or adverse factors (hypoxia, maternal infections during pregnancy, complicated labor). The underlying mechanism is sympathoadrenal system dysfunction and secondary adrenal cortex insufficiency.
• Manifestations: poor stress tolerance, unstable water-salt metabolism, and microcirculation problems. Minor developmental anomalies and underdevelopment (hypoplasia) of internal organs (heart, kidneys, blood vessels) are common.
• Prognosis: shifts are transient and usually resolve by puberty. If this does not occur, thymicolymphatic status develops. Such adults suffer from chronic hypotension, muscle weakness, and poor stress tolerance.

Nervous-arthritic diathesis

This is based on a genetic metabolic defect, predominantly in purine base and uric acid metabolism. The main pathogenetic factor is hyperuricemia (excess uric acid and urates).

The clinical picture is diverse and includes several syndromes:

• Neurological: high CNS excitability, tics, enuresis, emotional instability, sleep disorders, and sometimes anorexia or persistent vomiting.
• Articular: nocturnal joint pain due to the precipitation of urate crystals. Important to remember: true gouty arthritis does not occur in children.
• Urinary: excretion of salts (urates, oxalates, phosphates) and dysuria without signs of infection.

Triggering factors (aside from genetic enzyme defects, such as phosphoribosyltransferase) often include stress, overexertion, or an excess of protein (meat) in the diet of the mother or the child.

Acetone crisis

A specific complication of nervous-arthritic diathesis is acetonemic vomiting. It occurs predominantly in girls aged 2 to 10 years and completely resolves by puberty.

The crisis begins and ends suddenly. Vomiting becomes intractable, and a distinct acetone odor appears. The condition is accompanied by exicosis (dehydration), fever, tachycardia, and psychomotor agitation. In severe cases, seizures are possible.

Laboratory findings show:

• Acidosis (shift in acid-base balance).
• Excess acetone, ketone bodies, and ammonia.
• Decreased glucose levels (hypoglycemia) and electrolytes.

Treatment approaches and prognosis

In modern medicine, the term "diathesis" is considered obsolete. These conditions are viewed as a genetic predisposition, the manifestation of which depends on external triggers (maternal illness, poor ecology, drug overload).

Without the correct approach, there is a high risk of developing hypertension, atherosclerosis, gout, diabetes mellitus, bronchial asthma, cholelithiasis, and urolithiasis in adulthood. In relatives of children with nervous-arthritic diathesis, these diseases occur very frequently (in 18–22% of cases).

The basis of management for such patients is strict diet therapy, a protective regimen, and balanced pharmacotherapy to prevent adaptation failure.

Class and exam questions

What else to study on this topic

• Pathogenesis of the atopic march
• Minor developmental anomalies in lymphatic-hypoplastic diathesis
• Purine metabolism enzymopathies (hypoxanthine-guanine phosphoribosyltransferase deficiency)
• Principles of diet therapy in various types of diathesis

Other topics in "Chapter 3. Adaptation, Early Childhood Nutrition, Rickets"

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.