Hypoanesthetic Halos In Hawaii: Invasion of the Thrips…

And now for something completely different…  When I was at Tripler Army Medical Center I saw a number of patients present with Hypoanesthetic Halos in Hawaii, also referred to as Thysanoptera dermatitis.  It is a very unique presentation.  It is believed to be caused by Thrips which are small winged insects in the order Thysanoptera which comprises more than 5000 species ranging in size from 0.5 to 15 mm…most are approximately 1 mm in size. The insects typically feed on plants but are attracted to humidity and the sweat of animals and humans.  Here are some of my photographs…

HISTORICAL:  A case series was initially reported by Godstein and Skipworth (Papular eruption secondary to thrips bites.  JAMA 1968;203:53-55) in 1968.  Aeling published another case series (Aeling JL.  Hypoanesthetic halos in Hawaii. Cutis.  1974;14:541-544.) where he coined the term hypoanesthetic halos in Hawaii in 1974.  It is well known in the dermatology community in Hawaii.  The best review of this unusual disorder was reported by Carness, et al. in 2016 (Carness JM, et al.  Night of the living thrips:  An unusual outbreak of thysanoptera dermatitis.  Cutis.  2016;97:E13-E16…to see this article click HERE).  It has been my experience that the military is particularly predisposed to large outbreaks while in the field doing maneuvers.

UNIQUE FEATURES:  The bites occur at night and frequently at exposed sites, such as the face, neck and dorsal aspects of the hands.  Patients often develop erythematous macules and papules that have a characteristic halo around them.  Some experience decreased sensation to the halo regions that was referred to as hypoanesthesia by Aeling.  I have noted this in my patients.  Sooooo…if you are planning a hiking vacation to the Hawaiian Islands be advised…beware of the Thrips…