A 28-year-old man presents with a 4-week history of severe pruritus and multiple erythematous papules on his hands, wrists, axillae, and groin. Dermoscopy reveals linear burrows with a characteristic mite at the anterior end. He reports that his roommate, who shares the same bed, developed similar symptoms 2 weeks earlier. The patient has been applying topical corticosteroids for the past 2 weeks without relief. What is the most likely complication that may develop if treatment is delayed further?