Immediate and Medium-Term Impact of Bilateral Thoracic Sympathectomy on the Thermoregulatory Capacity of Patients with Focal Hyperhidrosis: The Contribution of Thermography to Patient Evaluation

Primary focal hyperhidrosis is a dysfunction of the autonomic nervous system, characterized by excessive sweating and alterations in peripheral vasomotor control.
For this study, we developed a graphical application based on Python and Raspberry Pi for real-time thermal monitoring. Designed for clinical use, the system integrates temperature sensors and an intuitive interface, enabling the detection of thermal variations and automatic alert generation, thereby facilitating the objective collection of data in the study of hyperhidrosis.

We began with a comparative study using infrared thermography to assess cutaneous temperature responses to gradual increases in ambient temperature in patients with hyperhidrosis versus healthy controls. The results showed a reduced increase in skin temperature in the palms and axillae of patients with hyperhidrosis, suggesting an exaggerated sympathetic adrenergic tone at the level of arteriovenous anastomoses. This blunted thermal response supports the hypothesis of autonomic dysfunction with adrenergic predominance, implying impaired thermoregulatory capacity.

Subsequently, we conducted a longitudinal study to evaluate the impact of T2–T4 thoracoscopic sympathectomy in paediatric patients, with thermographic recordings obtained preoperatively, and at 24 hours, three months, and six months post-intervention. An immediate increase in palmar temperature was observed, reflecting the interruption of vasoconstrictor sympathetic tone. Over time, temperatures progressively approximated those of the control group, suggesting a selective recovery of adrenergic tone without recurrence of sweating. These findings support a differential effect of sympathectomy on adrenergic and cholinergic pathways.

Taken together, these three studies validate infrared thermography as a valuable tool for the diagnosis and longitudinal monitoring of hyperhidrosis.

Keywords: Primary focal hyperhidrosis; thoracic sympathectomy; infrared thermography; thermoregulation; paediatric surgery ; body temperature regulation; sympathetic nervous system; termography.

Read the full version at: https://repositorio-aberto.up.pt/handle/10216/167308

Fátima Carvalho is a Medical Doctor specialized in Pediatric Surgery, with a PhD in Medical Sciences from ICBAS-UP, where she also teaches in the Integrated Master’s in Medicine. She was Director of the Pediatric Surgery Department at ULSSA (2013–2025) and, since 2025, has been Director of Knowledge Management.
A Senior Graduate Assistant in the medical career, she has training in management, clinical leadership, and medical law. She has held various positions within the Portuguese Medical Association, including President of the Disciplinary Board (2017–2022), and is currently a member of the Higher Council (2023–2025).