The incorrect statement regarding corticosteroids in allergy is:

Correct Answer: A

Rationale: The mechanism of corticosteroids is well understood; they modulate immune response by suppressing inflammation through inhibition of cytokines and prostaglandins.

Correct Answer: B

Rationale: Rheumatic polyarthritis predominantly affects large joints, not equally large and small joints.

Correct Answer: A

Rationale: Early introduction of fish, eggs, meat, and wheat has been shown to decrease allergy risks. However, rye has not been found to provide a protective effect and may sometimes contribute to allergic responses.

Correct Answer: D

Rationale: Major depression includes core symptoms like weight changes, sleep disturbances, and dysphoric mood. All listed options are possible features of the disorder.

Correct Answer: D

Rationale: Dennie-Morgan folds are characteristic infraorbital creases seen in children with atopic dermatitis or allergic rhinitis.