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tus. The condition frequently occurs in immunocompromised patients. In patients with HIV, this diagnosis can be obscured by concomitant dermatologic diseases, such as seborrhoeic dermatitis, xerosis or HIV-associated pruritus. Differential diagnoses also include ichthyosis, psoriasis, contact dermatitis, eczema, drug eruption or Darier’s disease. The diagnosis of this infestation might often be delayed given that its pathogenesis includes a shift from a Th1 to Th2 response showing a delayed hypersensitive reaction, symptoms that begin 4 weeks after initial infestation and the appearance of the crusted plaques 8–12 weeks thereafter. Treatment should include ivermectin, which is similar to macrolide antibiotics. This treatment induces paralysis and death in parasites by interrupting glutamate and c-aminobutyric acid neurotransmission. This medication is used in doses of 200 mcg/kg with a repeated dose 7–10 days after the initial dose. Conventional diagnosis with dermoscopy reveals a brownish triangular structure that corresponds to the head and breastplate of the mite and air-filled burrows along the parasite resemble a jet with a contrail. Dermoscopy of crusted scabies reveals several burrows excavated by multiple parasites present in immunosuppressed hosts. Crusted scabies dermoscopy has been described with single burrows, but there has been no description of this distinctive burrow over burrow pattern resembling a noodle pattern. Dermoscopy for scabies diagnosis allows a sensitivity of 91% and a specificity of 86%, making it a viable method for diagnosis. Once dermoscopic diagnosis of crusted scabies with a burrow over burrow pattern is made, there might be no need for any other diagnostic intervention. The importance of a prompt crusted scabies diagnosis relies on the fact that nosocomial outbreaks can occur. This diagnosis should be made with the aid of skin scraping, dermoscopy or a biopsy. If the infestation is in its early stages, skin scraping might not reveal the mites, hence the importance of the dermoscopic examination in these instances. S. Chavez-Alvarez, A. Villarreal-Martinez,* G. Argenziano, J. Ancer-Arellano, J. Ocampo-Candiani Dermatology Department, School of Medicine, Hospital Universitario ‘Dr. Jose Eleuterio Gonzalez’, Universidad Autonoma de Nuevo Le on, Monterrey, Nuevo Leon, Mexico, Dermatology Unit, University of Campania, Naples, Italy *Correspondence: A. Villarreal-Martinez. E-mail: dravillarrealmtz@ yahoo.com.mx