That is a bit of bad luck. Rainbow boas actually require quite high humidity as part of their husbandry and therefore generally tend to be somewhat "immune" to this condition. In my experience blister disease tends to be more randomly spread over an area. From your photos the affected areas look quite localized and I would not rule out thermal injury (burns) as the cause. Regardless of the cause, the treatment I outlined in the previous post on blister disease would still apply. I would encourage you to use the Silvadene ( 1% silver sulfadiazine) as your first choice and Betadine ointment as your second. In addition to being effective anti-bacterials both also have anti-fungal properties.