A 17-year-old boy comes to the office for evaluation of a rash. For the past 2 years, the patient has had recurrent skin bumps that are frequently red and painful. He has no other medical conditions and takes no medications. Vital signs are within normal limits. Skin examination findings are shown below. This patient's skin condition primarily affects which of the following structures?

Question

A 17-year-old boy comes to the office for evaluation of a rash.  For the past 2 years, the patient has had recurrent skin bumps that are frequently red and painful.  He has no other medical conditions and takes no medications.  Vital signs are within normal limits.  Skin examination findings are shown below.  This patient's skin condition primarily affects which of the following structures?

Quizplus · Accepted Answer

11ec160b_38ed_c2d7_9249_f16b322c0ae4_MD0001_00 This patient has typical features of acne vulgaris. Acne usually appears in adolescence and can present with a variety of lesions, including comedones, papules, pustules, or inflammatory nodules, often with lesions in different stages concurrently. Nodular (sometimes called nodulocystic) acne, as in this patient, is often painful, difficult to treat, and can lead to the formation of sinus tracts and residual scarring. Acne vulgaris is characterized by inflammation of pilosebaceous follicles. Contributing factors include hyperkeratinization and obstruction of follicles; sebaceous gland enlargement with increased sebum secretion; colonization of the gland by Propionibacterium (Cutibacterium) acnes, which metabolizes lipids in sebum and produces proinflammatory factors; and follicular and perifollicular inflammation with follicular rupture. (Choice A) Dermatitis herpetiformis most commonly occurs in patients with celiac disease and is characterized by microabscesses containing fibrin and neutrophils at the dermal papillae tips. Clinical manifestations include pruritic papules, vesicles, and bullae that appear symmetrically on the extensor surfaces (eg, elbows, knees), upper back, and buttocks. (Choice B) Eccrine sweat glands produce watery sweat in response to exertion, high ambient temperature, and emotional stress. The secretions from eccrine glands have little lipid content and do not support heavy colonization by P acnes; therefore, these glands do not have a prominent role in the pathogenesis of acne. (Choice C) Bullous pemphigoid is characterized by an autoimmune process that causes the epidermis to separate from the dermis, forming subepidermal blisters. It presents with tense, fluid-filled bullae on the inner thighs, forearms, axillae, groin, and abdomen. (Choice D) Melanocyte disorders typically present with hyperpigmentation (eg, melasma) or hypopigmentation (eg, vitiligo). (Choice F) Erythema nodosum-characterized by painful, subcutaneous nodules, typically in the lower legs-is a form of panniculitis (inflammation of the subcutaneous adipose tissue) caused by a delayed hypersensitivity reaction to antigens associated with various conditions (eg, herpes simplex). Educational objective: Acne vulgaris is an inflammatory disorder of pilosebaceous follicles. Contributing factors include hyperkeratinization and obstruction of follicles; sebaceous gland enlargement with increased secretion of sebum; colonization and proliferation in the gland by Propionibacterium (Cutibacterium) acnes; and follicular and perifollicular inflammation. __________ References: Acne pathogenesis: history of concepts. (http://www.ncbi.nlm.nih.gov/pubmed/25228295)

A 17-Year-Old Boy Comes to the Office for Evaluation of a Rash