Bullous eruption in a patient of scabies: rare presentation of a common disease

Scabies is a contagious infestation caused by the mite Sarcoptes scabiei and affecting all races and social classes. It is a common parasitic infection; the diagnosis is trivial when presentation is classical. However, unusual clinical variants such as crusted, hidden, incognito, bullous and nodular forms may mimic non-parasitic dermatoses and pose a diagnostic challenge [1]. A high index of suspicion and demonstration of the mite and/or its eggs in such cases can help to clinch the diagnosis. Herein, we report a case of scabies presenting with bullous eruption.
A 35-year-old male presented with multiple blisters mainly over the upper extremity and axillae for 20 days. Blisters appeared over itchy erythematous skin and ruptured on scratching to leave behind raw areas which developed crusting and some healed with hypopigmentation. There was a history of generalised itching which preceded the bullous eruption by 10 days. It was more intensive during the night and affected other family members as well. The patient denied any history of drug intake. He was otherwise well and had no chronic illness.
General physical and systemic examination was within normal limits. Cutaneous examination revealed multiple tense vesicles and bullae filled with clear fluid present over an erythematous base on the upper limbs, axillae and upper back. Haemorrhagic crusting and areas of hypopigmentation suggestive of old healed lesions were also noted (figs. 1 A, B). Nikolsky’s sign was negative. Excoriated papules were present over the abdomen and finger webs (figs. 1 C, D). Mucosal examination was normal. Scraping from the finger webs demonstrated scabies mite. Histopathology of the bulla revealed a subepidermal split with inflammatory infiltrate comprising of lymphocytes and eosinophils (figs. 2 A, B). Immunofluorescence could not be performed due to financial constraints. Diagnosis of bullous scabies was made and the patient was given 5% permethrin lotion for local application and antihistamines. Pruritus improved but bullous lesions continued to appear. Oral steroids were then administered in tapering doses with healing of the bullous lesions and remission in the appearance of fresh lesions.
Scabies classically presents with nocturnal pruritus and pleomorphic skin lesions as burrows, excoriated papules, nodules and as thick crusted plaques in crusted scabies. Impetigo, folliculitis, eczematisation and urticaria can occur as complications. Bullous lesions in...


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