News that the German Alpine Club has seen a sharp increase in the number of mountain huts infested with "bed bugs" reminded me of an old story about a trekker who went on a 3 week walking holiday to Patagonia.
Shortly after arriving in Ushuaia this previously fit and well young man noticed a series of red papules appear on his upper limbs, chest and neck. Each day their number increased and by the end of the trip hundreds of discrete papules had appeared across the trekker's upper body. As time passed these became increasingly itchy and needed treating with an oral anti-histamine. Unfortunately new papules continued to develop on the trekkers return home and more worryingly, they also started to appear on his partner!
The adult "bed bug" Cimex Lectularius is a red-brown, wingless, oval-shaped insect measuring about 4 to 5 mm in length. They are hematophagous ectoparasites that preferentially feed on human blood. Cimex Lectularius do not live on humans and only visit to feed. They live in dark locations and attack when humans are inactive for long periods of time. Since pesticide resistance is on the increase, eradication is best achieved by washing and drying infested fabrics at >60 degrees C and heating rooms to at least 50 degrees C for 90 minutes.
A diagnosis of bed bug bites was made following an inspection of the trekker's sleeping bag and liner. This revealed the presence of blood staining and large numbers of insects. Thorough washing of all infested fabrics was carried out together with a rather expensive course of professional extermination in the trekker's home. Within days the papules started to recede and the trekker (and his partner!) went on to make a full recovery.
"Bed bug" bites are often clustered in groups of 3 - the "breakfast, lunch and dinner" sign. This can sometimes help distinguish infestation from other urticarial rashes. Bites only occur on exposed skin - typically arms, chest and neck. The presence of papules around the eyes, the "eyelid sign", strongly points towards a "bed bug" infestation. Symptomatic treatment is normally all that is required however secondary bacterial infection can occur.
A very good review of bed bug infestation can be found here.
The British Mountain Medicine Society (BMMS) are organising a Science Day in the Peak District on the 13th November 2019. Why not come along? Details can be found here.