A 26-year-old woman comes to the office due to a skin condition. The patient has had dry, flaky skin since childhood, but it has worsened in recent years. Symptoms are typically worse in the winter but improve as the weather warms in the spring. The patient has a family history of asthma; both parents also have chronically dry skin. Examination shows diffuse scaling of the skin that is most notable on the extremities, as shown in the exhibit.
Which of the following is most likely contributing to this patient's condition?

Question

A 26-year-old woman comes to the office due to a skin condition.  The patient has had dry, flaky skin since childhood, but it has worsened in recent years.  Symptoms are typically worse in the winter but improve as the weather warms in the spring.  The patient has a family history of asthma; both parents also have chronically dry skin.  Examination shows diffuse scaling of the skin that is most notable on the extremities, as shown in the exhibit. 
 Which of the following is most likely contributing to this patient's condition?

Quizplus · Accepted Answer

This patient has diffuse dermal scaling consistent with ichthyosis vulgaris, an inherited disorder caused by mutations of the filaggrin gene. This results in epidermal hyperplasia and defective keratinocyte desquamation, leading to the accumulation of dry, scaly skin with loss of normal barrier function. Filaggrin mutations are also seen in atopic eczema, and ichthyosis vulgaris is frequently associated with a family history of eczema and other atopic disorders (eg, asthma, seasonal allergies). Ichthyosis vulgaris typically affects the trunk and extensor surfaces of the extremities (particularly the legs), with sparing of the flexures and face. Palmar hyperlinearity is also common. The symptoms first appear in childhood but may worsen with age, as well as in the winter because of decreased ambient humidity; mild symptoms may be misdiagnosed as simple xerosis (ie, dry skin). (Choice A) An androgen-induced increase in sebum production causes acne vulgaris, which presents with comedones, inflammatory papules, pustules, and nodules during adolescence. Diffuse scaling is not characteristic. (Choice B) Autoantibodies against desmogleins 1 and 3 cause pemphigus vulgaris, which is characterized by flaccid bullae that easily rupture to form erosions. Scaling is not characteristic. (Choice D) Excessive collagen deposition is seen in systemic sclerosis (ie, scleroderma). Systemic sclerosis presents with diffuse thickening and hardening of the skin, often associated with ulcerations at the fingertips. (Choice E) Allergic contact dermatitis is a type IV (T-cell-mediated) hypersensitivity reaction triggered by a variety of allergens (eg, poison ivy, natural rubber). It typically presents acutely within 2-4 days of exposure with a localized, pruritic, erythematous rash with vesicles and small bullae. Educational objective: Ichthyosis vulgaris is caused by filaggrin gene mutations that result in defective keratinocyte desquamation. It is characterized by dry, scaly skin; manifestations are diffuse but are typically worse on the trunk and the extensor surfaces of the extremities. __________ References: Ichthyosis vulgaris: the filaggrin mutation disease. (http://www.ncbi.nlm.nih.gov/pubmed/23301728)

A 26-Year-Old Woman Comes to the Office Due to a Skin