Corticosteroids are synthetic analogs of adrenal cortex hormones used for their potent anti-inflammatory and immunosuppressive effects.

They mimic:

• Cortisol (glucocorticoid activity)
• Aldosterone (mineralocorticoid activity – some agents)

Used across systems:

• Allergic Rhinitis
• Urticaria
• Asthma
• Autoimmune disease
• Dermatologic conditions
• Transplant medicine

• Prednisone
• Prednisolone
• Methylprednisolone
• Dexamethasone
• Hydrocortisone

• Fluticasone
• Budesonide
• Mometasone
• Triamcinolone

• Various potency classes

Corticosteroids act via intracellular glucocorticoid receptors.

Stepwise:

1) Drug diffuses across cell membrane
2) Binds cytoplasmic glucocorticoid receptor
3) Complex translocates to nucleus
4) Alters gene transcription

Results:

• ↓ Pro-inflammatory cytokines (IL-1, IL-2, IL-4, IL-5, IL-6, TNF-α)
• ↓ Eosinophil survival
• ↓ T-cell activation
• ↓ Mast cell mediator release
• ↓ Prostaglandin synthesis (via ↓ phospholipase A2)
• ↓ Leukotriene production

Effect:

Broad suppression of inflammation.

Onset:

• Hours to days (genomic mechanism)

Clinical relevance:

• Mineralocorticoid activity → fluid retention, hypertension
• Dexamethasone preferred when fluid retention undesirable

Type I hypersensitivity late-phase control:

• Late Phase Reaction

Allergic rhinitis:

• Intranasal first-line

Asthma:

• Inhaled maintenance therapy

Severe allergic reactions:

• Adjunct in anaphylaxis (not first-line)

Autoimmune and inflammatory disease:

• Broad use

Short-term:

• Mood changes
• Hyperglycemia
• Fluid retention
• Insomnia

Long-term:

• Adrenal suppression
• Osteoporosis
• Cushingoid appearance
• Muscle wasting
• Increased infection risk
• Peptic ulcer disease

Mechanism:

Systemic immunosuppression and metabolic alteration.

Chronic steroid use suppresses endogenous cortisol production.

Abrupt withdrawal may cause:

• Adrenal insufficiency
• Hypotension
• Fatigue
• Crisis in severe cases

Taper when:

• High dose
• Prolonged use (>2–3 weeks)

• Intranasal corticosteroids are superior to oral antihistamines for nasal congestion.
• Steroids suppress late-phase allergic inflammation.
• Dexamethasone has no mineralocorticoid activity.
• Always consider HPA suppression with prolonged systemic therapy.
• In anaphylaxis, epinephrine is first-line — steroids are adjunctive.

• Histamine & Antihistamines
• Type I Hypersensitivity
• Epinephrine