A 7-year-old boy is brought to the office due to hair loss. For the last few weeks, he has had worsening hair loss in patches on the scalp. There is no associated pain or itching. Medical history is unremarkable, and the patient's height and weight have consistently tracked at around the 30th percentile for age. He has achieved developmental milestones within the normal range and has had no significant academic issues at school. Skin examination findings are as shown in the exhibit. Which of the following is the most likely cause of this patient's hair loss?

Question

A 7-year-old boy is brought to the office due to hair loss.  For the last few weeks, he has had worsening hair loss in patches on the scalp.  There is no associated pain or itching.  Medical history is unremarkable, and the patient's height and weight have consistently tracked at around the 30th percentile for age.  He has achieved developmental milestones within the normal range and has had no significant academic issues at school.  Skin examination findings are as shown in the exhibit.  Which of the following is the most likely cause of this patient's hair loss?

Quizplus · Accepted Answer

11ec25c8_d645_10fe_bc81_373391fad27c_MD0003_00 This patient has patchy, painless hair loss consistent with alopecia areata (AA). The hair loss in AA develops over weeks in discrete patches with smooth skin and no associated erythema, scaling, or scarring. AA is an autoimmune disorder; it may occur in isolation but can also be associated with other autoimmune conditions (eg, vitiligo, systemic lupus erythematosus, autoimmune thyroid disease). The diagnosis of AA is usually based on visual inspection (often with the assistance of dermatoscopy); close inspection may show narrowing of the hair shafts close to the skin surface (exclamation point hairs). The hair pull test is often positive as well (a cluster of ~50 hair fibers is pulled firmly; extraction of >5 or 6 strands is abnormal). Treatment includes topical or intralesional corticosteroids. A recurring course is common, but most patients have regrowth over time. exclamation point hairs (Choice B) Discoid lupus erythematosus of the scalp causes hair loss with inflammation, scarring, and hypopigmentation of the skin. There are often additional lesions on the face or extremities. inflammation, scarring, and hypopigmentation (Choice C) Pediculosis capitis (head lice infestation) presents with pruritus of the scalp and visible nits. It is not typically associated with hair loss. visible nits (Choice D) Telogen effluvium is characterized by diffuse, rather than patchy, hair loss. It is often triggered by physiologic stressors (eg, severe illness, pregnancy, endocrine disorders) or emotional distress. (Choice E) Tinea capitis is a superficial dermatophyte infection that presents as a scaly, erythematous patch of hair loss. There are often small, black dots, representing broken shafts, and (sometimes) tender lymphadenopathy. small, black dots (Choice F) Trichotillomania is characterized by self-induced hair pulling. It causes patchy hair loss, but usually shows signs of regrowth with new hair shafts of various lengths. It commonly occurs on the patient's dominant side (ie, usually right). regrowth Educational objective: Alopecia areata is characterized by patchy, painless hair loss with no erythema, scaling, or scarring. It is an autoimmune disorder and is often associated with other autoimmune conditions (eg, autoimmune thyroid disease). Treatment includes topical or intralesional corticosteroids. A recurring course is common, but most patients have regrowth over time. References: Alopecia areata. (http://www.ncbi.nlm.nih.gov/pubmed/28300084)

A 7-Year-Old Boy Is Brought to the Office Due to Hair