An 8-year-old previously healthy girl is brought to the office by her mother due to hair loss on the scalp. Several weeks ago, the mother noticed the patch of hair loss, which has progressively enlarged. The mother also says that the girl frequently scratches at the area. The child recently changed to a different school and has been anxious about new teachers and friends. Skin examination findings are shown in the image below. There are several enlarged, tender, occipital and posterior auricular lymph nodes. Which of the following is the most likely cause of this patient's condition?

Question

An 8-year-old previously healthy girl is brought to the office by her mother due to hair loss on the scalp.  Several weeks ago, the mother noticed the patch of hair loss, which has progressively enlarged.  The mother also says that the girl frequently scratches at the area.  The child recently changed to a different school and has been anxious about new teachers and friends.  Skin examination findings are shown in the image below.  There are several enlarged, tender, occipital and posterior auricular lymph nodes.  Which of the following is the most likely cause of this patient's condition?

Quizplus · Accepted Answer

11ec25c8_d64e_d514_bc81_333bdfdfba2d_MD0003_00 This patient has tinea capitis (TC), a dermatophyte infection occurring most commonly in children and immunocompromised patients. The most common form in the United States is black dot TC (BDTC), which is due to Trichophyton tonsurans, but other dermatophytes (eg, Microsporum canis, Microsporum audouinii) can also cause TC. Although TC can affect all races, BDTC is most common in African Americans. Transmission is usually through human-to-human contact or fomites (eg, shared combs). Patients develop an initial scaly, erythematous plaque on the scalp that can progress to patchy alopecia with a residual black dot (broken hair). Other findings can include inflammation, pruritus, occipital or postauricular lymphadenopathy, and scarring. TC is often diagnosed clinically but can be confirmed with potassium hydroxide (KOH) examination of hair stubs. Oral griseofulvin or terbinafine is preferred in most patients. As dermatophyte carriers can be asymptomatic, many experts recommend that household contacts be treated with selenium sulfide or ketoconazole shampoo. (Choice A) Common autoimmune causes of alopecia include alopecia areata, which causes smooth circular areas of hair loss without scaling, and discoid lupus erythematosus, which presents with well-demarcated inflammatory plaques, hypo- or hyperpigmented lesions, scarring, and photosensitivity. alopecia areata discoid lupus erythematosus (Choice B) Cutaneous candidiasis causes an erythematous, vesiculopapular rash in warm, moist areas (eg, skinfolds). It rarely affects the scalp. Cutaneous candidiasis (Choice D) Pressure-induced (postoperative) alopecia is due to prolonged pressure on the scalp during surgical procedures. Transient hair loss develops a few weeks after the surgery, followed by regrowth without significant residual alopecia. (Choice E) Trichotillomania is due to repeated plucking of hair, leading to an irregular pattern of broken hair strands of varying length. (Choice F) Seborrheic dermatitis causes a scaly, oily, erythematous rash affecting the skinfolds around the nose, eyebrows, and ears. Involvement of the scalp is commonly referred to as dandruff. Educational objective: Tinea capitis is a superficial dermatophytosis that most commonly occurs in children and immunocompromised patients. It causes a scaly, erythematous patch that can progress to alopecia with inflammation, lymphadenopathy, and scarring. Oral griseofulvin or terbinafine are the preferred initial treatment options. References: Tinea capitis: diagnostic criteria and treatment options. (http://www.ncbi.nlm.nih.gov/pubmed/19873694) Superficial fungal infections. (http://www.ncbi.nlm.nih.gov/pubmed/22474120)

An 8-Year-Old Previously Healthy Girl Is Brought to the Office