A patient presents with a pruritic rash with linear streaks and small, fluid-filled blisters. The patient reports recent exposure to poison ivy while gardening. Which of the following conditions is most likely responsible for this presentation?

Correct Answer: B

Rationale: The presentation of a pruritic rash with linear streaks and small, fluid-filled blisters following exposure to poison ivy is characteristic of allergic contact dermatitis. Poison ivy contains an oil called urushiol, which is known to cause this type of skin reaction in individuals who are sensitive to it. The linear streaks are often a result of the plant brushing against the skin. Pemphigus vulgaris is an autoimmune condition characterized by the formation of intraepidermal blisters, typically not associated with linear streaks or exposure to irritants like poison ivy. Bullous pemphigoid is characterized by subepidermal blisters, and herpes zoster presents with a painful rash following reactivation of the varicella-zoster virus in a dermatomal pattern, not typically in linear streaks.

Correct Answer: A

Rationale: Molluscum contagiosum is a viral skin infection caused by the poxvirus. It typically presents as multiple, flesh-colored, dome-shaped papules with a central umbilication (dimple or depression in the center) on the skin. These lesions are often found on the trunk and extremities and can persist for several months. Molluscum contagiosum is commonly seen in children but can also occur in adults, especially those with weakened immune systems. The lesions are usually asymptomatic but can become inflamed or itchy in some cases. Treatment options include observation, topical therapies, cryotherapy, or curettage.

Correct Answer: B

Rationale: Acute otitis media is the most likely condition responsible for this presentation. The sudden onset of severe, unilateral ear pain, diminished hearing, and purulent otorrhea are classic symptoms of acute otitis media. Otoscopic examination revealing a bulging, erythematous tympanic membrane with obscured landmarks further supports the diagnosis. The bulging of the tympanic membrane is due to the accumulation of fluid and pus behind it, causing the characteristic appearance. Treatment typically involves antibiotics to help clear the infection and relieve symptoms. If left untreated, acute otitis media can lead to complications such as perforation of the eardrum or mastoiditis.

Correct Answer: C

Rationale: The presentation described with a sensation of fullness and pressure in the left ear, along with hearing loss and occasional tinnitus, and the findings of a retracted tympanic membrane with decreased mobility on pneumatic otoscopy are most consistent with serous otitis media, also known as otitis media with effusion (OME). OME is characterized by the presence of non-infected fluid in the middle ear space, leading to symptoms such as ear fullness, hearing loss, and occasionally tinnitus.

Correct Answer: C

Rationale: The presentation described in the question (sensation of fullness and pressure in the left ear, hearing loss, occasional tinnitus, retracted tympanic membrane with decreased mobility on pneumatic otoscopy) is suggestive of serous otitis media, also known as otitis media with effusion. Serous otitis media occurs when fluid accumulates in the middle ear without signs of infection. This buildup of fluid in the middle ear space can cause the tympanic membrane to retract and reduce its mobility on pneumatic otoscopy.