A 14-year-old boy is brought to the office due to a rash lasting 3 weeks. The patient first noted red spots on his arms and legs that itched and burned; these have since filled with clear fluid, and some have crusted over. He has also had less energy to participate in after-school activities. The patient has lost 3.6 kg (8 lb) in 4 months. Physical examination shows conjunctival pallor and an erythematous, vesicular, symmetrically distributed rash over the extensor surfaces of the elbows and knees. Laboratory results are as follows: Fecal occult blood testing is negative on 3 samples. Which of the following is the best next step in management of this patient?

Question

A 14-year-old boy is brought to the office due to a rash lasting 3 weeks.  The patient first noted red spots on his arms and legs that itched and burned; these have since filled with clear fluid, and some have crusted over.  He has also had less energy to participate in after-school activities.  The patient has lost 3.6 kg (8 lb) in 4 months.  Physical examination shows conjunctival pallor and an erythematous, vesicular, symmetrically distributed rash over the extensor surfaces of the elbows and knees.  Laboratory results are as follows:  Fecal occult blood testing is negative on 3 samples.  Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

11ec25c8_d26a_4799_bc81_df38326d7b2c_MD0003_00 This patient has weight loss, a vesicular rash, and fatigue with iron deficiency anemia, findings concerning for celiac disease. Celiac disease is an immune-mediated hypersensitivity to gluten that leads to impaired nutrient absorption in the proximal small intestine. Classic symptoms include abdominal pain, bloating, diarrhea, and/or weight loss. However, extraintestinal symptoms with no gastrointestinal features may be the sole presentation, as seen in this patient. For example, poor iron absorption secondary to duodenal villous atrophy can lead to iron deficiency anemia (microcytosis, ↓ ferritin) and symptoms of fatigue or pallor. Dermatitis herpetiformis is another extraintestinal manifestation and presents as grouped pruritic papules or vesicles (eg, fluid-filled) typically on extensor surfaces (eg, elbows, knees). Erosions and excoriations due to pruritus may be observed. Dermatitis herpetiformis Celiac disease can be diagnosed by elevated tissue transglutaminase IgA antibody levels and duodenal biopsy showing villous atrophy and crypt hyperplasia. Symptoms typically respond to a gluten-free diet; dapsone should also be given for acute management of dermatitis herpetiformis. (Choice A) Systemic lupus erythematosus, in which antinuclear antibodies are positive, can cause weight loss, fatigue, photosensitivity, and a malar rash. A vesicular rash on the extensor surfaces would not be expected, and normocytic, not microcytic, anemia due to chronic disease is typical. (Choice B) Streptococcal infection (eg, pharyngitis), which increases antistreptolysin O antibodies, can be associated with erythema nodosum. Unlike findings in celiac disease, findings in streptococcal infection include painful, nonpruritic nodules on the shins. It would not typically cause microcytic anemia. (Choice C) Histologic changes in celiac disease are found in the proximal small bowel, warranting upper endoscopy, not colonoscopy. In addition, although this patient has microcytic anemia, his negative fecal occult blood test makes occult lower gastrointestinal tract pathology less likely. (Choice D) Dermatologic findings in hepatitis C include lichen planus (purple, polygonal, pruritic, papular lesions) and porphyria cutanea tarda, a pruritic, blistering rash on sun-exposed areas (eg, hands, face). This patient's rash distribution and morphology make these diagnoses unlikely. Furthermore, iron deficiency anemia would not be expected with hepatitis C infection. (Choice E) Lead poisoning can cause weight loss and fatigue and can be associated with iron deficiency anemia. However, lead poisoning does not cause a rash and is uncommon beyond early childhood. Educational objective: Celiac disease may present without overt gastrointestinal symptoms. Extraintestinal manifestations include iron deficiency anemia and dermatitis herpetiformis, which is a papulovesicular rash on extensor surfaces. The diagnosis is supported by elevated tissue transglutaminase IgA antibody levels. References: Iron deficiency anemia in celiac disease. (http://www.ncbi.nlm.nih.gov/pubmed/26309349) ACG clinical guidelines: diagnosis and management of celiac disease. (http://www.ncbi.nlm.nih.gov/pubmed/23609613)

A 14-Year-Old Boy Is Brought to the Office Due to a Rash