Pyogenic Flexor Tenosynovitis as a Rare Complication of Dyshidrotic Eczema.

INTRODUCTION: Pyogenic flexor tenosynovitis is an unusual complication of dyshidrotic eczema. The diagnosis has traditionally been made by Kanavel's signs. Point-of-care ultrasound can be a useful adjunct in the diagnosis of this surgical emergency. CASE REPORT: We report the case of a 23-year-old male who presented with right middle finger pain and swelling and an overlying eczematous rash. The use of point-of-care ultrasound was performed to aid in the diagnosis of pyogenic flexor tenosynovitis. An incision and drainage was performed with deep wound cultures positive for Staphylococcus aureus. DISCUSSION: The presentation of pyogenic flexor tenosynovitis with underlying concomitant dermatological disease can complicate this challenging diagnosis. Point-of-care ultrasound can be an effective adjunct in revealing pyogenic flexor tenosynovitis rather than relying solely on the classical Kanavel's signs, leading to earlier treatment. CONCLUSION: Our case demonstrates that point-of-care ultrasound can be a rapid and effective tool for the diagnosis of pyogenic flexor tenosynovitis in the setting of superimposed dermatological diseases.

Substrate binding to the multidrug transporter MepA.

MepA is a multidrug transporter from Staphylococcus aureus that confers multidrug resistance through the efflux of a wide array of hydrophobic substrates. To evaluate the ability of MepA to recognize different substrates, the dissociation constants for interactions between MepA and three of its substrates (acriflavine (Acr), rhodamine 6G (R6G), and ethidium (Et)) were measured. Given that MepA is purified in the presence of detergents and that its substrates are hydrophobic, we examined the effect of the detergent concentration on the dissociation constant. We demonstrate that all three substrates interact directly with the detergent micelles. Additionally, we find the detergent effect on the KD value to be highly substrate-dependent. The KD value for R6G is greatly influenced by the detergent, whereas the KD values for Acr and Et are only modestly affected. The effect of the inactive D183A mutant on binding was also evaluated. The D183A mutant shows lower affinity toward Acr and Et.