Do mycobacterial infections cause any dermatologic emergencies?

Most mycobacterial infections are relatively chronic and do not constitute emergencies. However, when patients with Hansen’s disease (leprosy) are treated, they may undergo a “reversal reaction” that is secondary to a change in their immune status, resulting in acute inflammation of the involved areas. This may produce mild erythema and swelling of the skin and subcutaneous tissue. The apparent benignity of the situation belies its seriousness. The involved nerves are completely destroyed, resulting in permanent motor and sensory damage to the area. The lack of sensory input and resultant trauma over years lead to severe disfigurement of the extremities. Treatment consists of high-dose prednisone tapered over weeks.