Corticosteroids bind to glucocorticoid receptor, nuclear receptor on outer membrane of nucleus inside cell. Through this it’s translocated to nucleus and attaches to glucocorticoid response elements (promoter region for transcription – gene expression controlled).

Mode of action

• Anti-inflammatory• Vasoconstrictive• Decrease permeability of dermal vessels• Decrease phagocytic migration and activity• Decrease fibrin formation• Decrease kinin formation• Inhibit phospholipase A2 activity and decrease products of arachidonic acid metabolism• Depress fibroblastic activity• Stabilize lysosomal membrane• Immunosuppressive• Antigen – antibody interaction unaffected but inflammatory consequences lessened by above mechanisms and by inhibiting cytokines• Lympholytic• Decrease epidermal proliferation

Complications• Thinning of epidermis• Thinning of dermis• Telangiectasia and striae• Bruising (vessel wall fragility)• Hirsutism• Folliculitis and acneiform eruptions• May worsen or disguise infections (bacterial, viral and fungal)• Systemic absorption (rare but may be important in infants, when applied in large quantities under polyethylene pants)• Tachyphylaxis – lessening of clinical effect with the same preparation• Rebound – worsening, sometimes dramatic on withdrawing treatment