What condition is characterized by small, intensely itching blisters caused by an allergic reaction?

The condition characterized by small, intensely itching blisters due to an allergic reaction is contact dermatitis. This condition occurs when the skin comes into direct contact with a substance that triggers an allergic response or irritation. The blisters can form as part of the body's defense mechanism, resulting in inflammation.

Contact dermatitis typically presents with red, itchy, and swollen skin, and the blisters can emerge in response to various allergens such as certain plants (like poison ivy), metals (like nickel), or chemicals found in skin care products. The intense itching and blistering are key symptoms that differentiate it from other dermatitis-related conditions.

Other conditions listed have distinct characteristics: seborrheic dermatitis primarily exhibits oily, flaky patches rather than blisters and is more related to sebaceous gland activity; psoriasis is marked by thick, red patches with silvery scales and is a chronic autoimmune condition; eczema, although it also involves itching and inflammation, generally does not present with the intensely blistering reactions seen in contact dermatitis but rather tends to show dry, cracked skin. Thus, the defining characteristic of contact dermatitis is its direct correlation with specific allergens and the resultant blistering reaction.