Scabies link with pemphigoid investigated
medwireNews: Research suggests that patients who experience scabies infection may be at increased risk for developing the autoimmune blistering skin condition bullous pemphigoid.
The authors believe that "Sarcoptes scabiei may trigger a specific immune response activating T helper 2 cells, which would in turn increase the level of interleukin and eosinophils finally resulting in the secretion of proteolytic enzymes near the basement membrane leading to blistering."
They add: "This possibility is supported by prior studies and thus may explain the increased risk for pemphigoid among patients with scabies detected in this study."
Kuo-Hsien Wang (Taipei Medical University, Taiwan) and colleagues recruited 6793 individuals with scabies infection (mean age 54.1 years) and 33,965 randomly selected controls, none of whom had a prior history of pemphigoid. The controls were matched to the cases on the basis of gender, age group, geographical region, urbanization level, and year of scabies diagnosis.
As reported in the Journal of the European Academy of Dermatology and Venereology, the participants were followed up for 3 years for incident pemphigoid beginning at their first clinic visit after diagnosis with scabies or equivalent point in time for controls.
During the 6-year follow-up period, 52 individuals developed pemphigoid; 33 (0.49%) with scabies infection and 19 (0.06%) control participants.
Wang and team calculated that patients with scabies were a significant 5.93 times more likely to develop pemphigoid in the 3 years following scabies diagnosis than those without the infection, following adjustment for factors including monthly income and comorbidities such as hypertension, diabetes, obesity, psoriasis, and stroke.
To allow for the possibility that the symptoms of scabies can mimic those of pemphigoid, the team excluded any subjects diagnosed with pemphigoid within 3 months of scabies diagnosis. However, this did not substantially change the association and the risk for pemphigoid in patients with scabies remained significant and was 6.05 times higher than that of controls.
"Physicians treating elderly patients with a history of scabies should be alert to the development of pemphigoid," say Wang and co-workers. "Particular emphasis should also be placed on precautionary measures aimed at preventing the spread of scabies in institutionalized settings likely to host elderly individuals such as nursing homes."
By Helen Albert, Senior medwireNews Reporter