Clinical description and treatment outcomes of Paederus dermatitis in Phuentsholing, Bhutan in 2021: A cross-sectional study

Abstract

An increasing number of beetle population and outbreaks of irritant contact dermatitis are reported from newer geographic locations. Bhutan is one such country that witnessed an outbreak of Paederus dermatitis (PD) in Phuentsholing sub-district in 2021. This study describes the clinical symptoms, skin lesions and treatment outcomes of PD in Bhutan. This was a descriptive cross-sectional study of an outbreak of Paederus-related contact dermatitis in Phuentsholing, Bhutan. Clinical symptoms, skin lesions, duration of illness, recovery time and response to treatment were recorded. Of the 81 patients with PD, the males constituted 54% (44) and the mean age was 22 years (range: 1-51 years). The commonly affected groups were those aged 11-20 years (40.7%) and school or college students (50.6%). The common symptoms were pain, itching, redness, tenderness and blister formation. The lesions were erythematovesicular (70%), linear (54.3%) and kissing lesions (28.4%). All patients received some form of topical or oral steroid therapy and recovery was 100%. The mean duration from the onset till the recovery of the skin rash was 13 days (SD ± 8.3 days). PD outbreak is a self-limiting form of contact dermatitis. This is the first report of PD in the sub-Himalayan region and may be linked to climate change. There is a need for active surveillance and monitoring of such emerging weather/climate-related agents for appropriate health system response in disease prevention and treatment.

FIGURE 1

Time series of the outbreak of Paederus dermatitis in Phuentsholing, Bhutan, 2021.

FIGURE 2

Distribution of skin rash duration from the onset till recovery of Paederus dermatitis patients in Phuentsholing, Bhutan, 2021.

FIGURE 3

Skin lesions in patients with Paederus dermatitis. (a) Erythematovesicular rash on the left anterior forearm (a) and on the back with a ruptured blister at the centre (b). Linear dermatitis over the left lateral leg (c), the right side of the face (d) and on the right arm (e). Photo copyright: Authors.

FIGURE 4

Kissing lesions of Paederus dermatitis appear on opposing surfaces that come into contact. (a) Erythematovesicular kissing rash with central ulceration which is partially healed over the right antecubital area. (b) Kissing lesions over the right axillary region with pustules.

FIGURE 5

Paederus beetle spotted in homes in Phuentsholing, Bhutan in 2021. (a) Dorsal view, (b) ventral view. (Approximate dimension 8 × 1.5 mm).