Post ambulatory swollen hands (POTASH): a case report

Introduction

Post ambulatory swollen hands (POTASH) is an acquired, idiopathic condition that may develop in individuals after various types of ambulation including hiking, walking, or running (1,2). It is not dependent on the ambient temperature and only affects the distal upper extremities; it has not been observed to occur on the feet or toes. It is asymptomatic and typically occurs after an hour of ambulation; once, the ambulatory activity has been discontinued is frequently resolves spontaneously within a few hours (1,3).

POTASH was initially described by investigators studying Brazilian walkers (4). Magazines that are devoted to outdoor enthusiasts have also described this condition (5). There is an unexplained paucity of subsequent reports of POTASH in the medical literature; this suggests a lack of awareness of this condition. Albeit uncommon, additional patients with POTASH have been described in individuals participating in long distance races (2,6).

A man who developed asymptomatic swelling of his hands and digits while participating in a half marathon is described. Examination showed marked enlargement of his thumbs, fingers, and hands; within 2 hours after he stopped walking, his hands spontaneously returned to their normal size. Additional features of this recurrent and benign condition, such as the affected individual being unable to make a fist when he or she attempts to clench their fingers into their palm, are summarized (7). I present this case in accordance with the CARE reporting checklist (available at https://acr.amegroups.com/article/view/10.21037/acr-24-101/rc).

Case presentation

A 65-year-old man, on April 14, 2024, developed asymptomatic swelling of his fingers and hands while he was rapidly walking during a 13.1-mile half marathon race in San Diego, California; this had occurred during prior half marathons (1-3,6,7). He did not experience angioedema, hives, pruritus, or swelling at any other sites. At the start of the race, the ambient temperature was 47 degrees Fahrenheit; it had increased to 60 degrees Fahrenheit when he had completed the half marathon race 3 hours and 46 minutes later. Both of his hand and their digits began to swell after the first hour of running; during the remainder of the race, they had progressively become larger.

Mucocutaneous examination after he completed the race showed asymptomatic diffuse uniform swelling of the dorsal and ventral hands and fingers of both upper extremities (Figure 1). He could not close his hand into a fist, which is referred to as a positive fist sign. There was no urticaria and the swollen areas did not itch. Neither ocular nor oral mucous membranes were swollen; in addition, there was no swelling of the lips or periocular area.

Figure 1 POTASH. Dorsal (A,B) and palmar (C,D) views of the swollen left (A,C) and right (B,D) hands of a 65-year-old man who developed POTASH while walking a 13.1-mile race. The prominent enlargement of the fourth finger on the left hand (A,C) can be observed proximal and distal to his ring. He has a positive fist sign and is not able to clench his fingers into the palm of his hand (C,D). POTASH, post ambulatory swollen hands.

There was no additional swelling after he stopped walking. The swelling in both of his hands had completely resolved spontaneously within 2 hours after he stopped ambulating (Figure 2). Laboratory tests were not performed to rule out other conditions since the swelling rapidly completely resolved without any therapeutic intervention. He was again able to make a tight fist by clenching his fingers into his palm, which is referred to as a negative fist sign.

Figure 2 POTASH has completely resolved. Dorsal (A,B) views of the man’s hands demonstrate that within 2 hours after he finished the race and stopped walking the acute swelling spontaneously resolved. He now has a negative fist sign of both his left (C) and right (D) hand; he can tightly clench his fingers into the palm of each hand and make a fist. POTASH, post ambulatory swollen hands.

All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committees and with the Helsinki Declaration (as revised in 2013). Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

Discussion

POTASH was described by Ravaglia et al. in December 2011 and referred to as ‘big hand syndrome’. The investigators were initially attempting to assess the ownership prevalence and regular walking of dogs in Sao Paulo; when several of the subjects reported hand swelling following ambulation, the researchers expanded their pilot study and reported their observations in the rheumatology literature (4).

Big hand syndrome was studied in 1,009 subjects: 699 women and 410 men. Hand swelling developed in 202 (29%) of women and 67 (16%) of men. Hand swelling occurred more commonly in younger individuals and in dog owners. Duration of hand swelling was evaluable in 258 of the people; the swelling was transient (resolving within 1 to 2 hours after walking was finished) in 228 subjects (170 women and 58 men) and permanent (more than 2 hours) in 30 subjects (26 women and 4 men) (4).

Since the initial report of POTASH, the condition would occasionally be described in magazines focused on outdoor activities such as hiking and walking (5). However, nearly a full decade had passed when the next report of ambulation-related swollen hands was published in the medical literature in December 2021; the author coined the acronym POTASH to refer to the condition (1). To increase awareness of POTASH, the investigator has continued to report cases of the condition (2,3,6,7).

Asymptomatic swelling of the hands, thumbs, and fingers is the salient feature of POTASH; usually the swelling begins within an hour after the ambulatory activity has been started and it is not dependent on the ambient temperature. There is neither angioedema nor urticaria. Pruritus and pain are both absent. All the swelling occurs distally to the wrist; the proximal arm and the feet are not affected (1-4,6,7).

The swelling of the hand and the digits of a person with POTASH creates a situation that the affected individual cannot tightly clench their fingers into the center of their palms. Therefore, individuals with POTASH cannot make a fist and this is referred to a positive fist sign. Other conditions can also result in a positive fist sign; these include acromegaly, allergic contact dermatitis, Blau syndrome, compartment syndrome, giant lipoma with associated carpal tunnel syndrome, puffy hand syndrome resulting from intravenous drug use, remitting seronegative symmetrical synovitis with pitting edema, and squamous cell carcinoma (1,3,7-16).

There are several conditions that are either characterized by acute or chronic swelling of the hands. The causes of these conditions include bleeding, fibrosis, fluid overload, infection, nerve compression secondary to a space occupying lesion, obstruction of lymphatics, overgrowth of bone and soft tissue, trauma and urticaria. Therefore, POTASH is not only in the differential diagnosis of acute swelling of the hands, but also in the differential diagnosis of chronic hand swelling (1,3,7).

POTASH usually resolved spontaneously once the individual discontinues the associated ambulatory activity. Complete resolution of the swelling typically occurs within 1 or 2 hours. However, less frequently the swollen hands and digits persist for more than 2 hours, yet still eventually resolves. Once the swelling is gone, the individual is again able to make a tight fist, referred to as a negative fist sign (3,6,7).

The number of published papers in the medical literature is sparse regarding the occurrence of swollen hands resulting from ambulatory activities (5). To the best of my knowledge, including this report, only seven papers have been published (1-7). The limitation of this paper is that it is restricted to the observations of this condition in a single individual; additional prospective studies might be able to elucidate predisposing characteristics of people who develop POTASH and provide additional insight into the pathogenesis of this condition. The importance of this single report is that it provides a succinct and comprehensive description of the features of swollen hands associated with ambulatory activities in order enhance the awareness of clinicians who may encounter patients with this condition and allow them an opportunity to make the diagnosis and appropriately counsel the individual.

POTASH is a recurrent condition. In the man described in this report, the condition has occurred when he has participated on several prior half marathons; the ambient temperature has not influenced the development of the hand swelling (2-4,7).

Like most of the subjects with walking-associated hand swelling in Brazil, the POTASH-related swollen hands resolved completely within 2 hours after walking was stopped not only in the man described in this paper, but also in his wife (4,6). Also, like some of the patients described in the study from Brazil, POTASH was observed to persists longer in the man’s sister after completing a 13.1-mile race (6). Her hand swelling required 48 hours to resolve completely spontaneously (6).

The pathogenesis of POTASH remains to be established. The original investigators were only able to speculate the causative etiology eliciting the swollen hands that they observed in some of the individuals following walking. Some of the mechanisms included reduced venous return from the hand (similar to patients with carpel tunnel syndrome, Raynaud’s phenomenon, scleroderma and thoracic outlet syndrome), autonomic dysfunction (similar to patients who have experienced hand or brachial plexus trauma or individuals with complex regional pain syndrome type I), systemic neurogenic effect (similar to the patient who developed unexplained acupuncture treatment-related hand swelling), improper arm motion (secondary to excess fluid being mobilized into the hands from centrifugal forces) (4).

In addition to the Brazilian researchers, other authors have also postulated mechanisms for the pathogenesis of ambulation-related hand swelling (4,5). These include hyponatremia and vasodilation that was either cold-induced or heat-triggered. More recently, the possibility of a genetic predisposition to the development of POTASH has been suggested by the observation of the condition occurring in a brother and sister (6).

Prospective studies evaluating the prevalence of the condition in not only walkers, but also athletes who participate in sports that require running is warranted. Additional investigation into the pathogenesis of POTASH is warranted. The reason for the condition being limited to the upper extremity remains to be elucidated; perhaps swelling of the feet is prevented by the pressure of the individual’s footwear and wearing tight gloves might have a preventative effect on the development of POTASH in susceptible individuals.

Conclusions

Ambulatory activities, such as walking, hiking, and running, can result in the development of swollen hands. A man, who developed POTASH while participating in a half marathon is described; his hand swelling began after 1 hour of walking. In addition to his hands, his thumbs and fingers also became swollen, and he demonstrated a positive fist sign by not being able to clench his fingers into his palms to create a fist. Within 2 hours after he stopped walking, the swelling had spontaneously completely resolved, and he had a negative fist sign by being able to make a tight fist. POTASH is an acquired, temperature-nondependent, condition whose pathogenesis remains to be established; although several hypotheses have been speculated, a definitive etiology has not been confirmed. A report of occurrence of POTASH in a brother and sister, raises the possibility that the condition may have a hereditary component. POTASH is not uncommon; the occurrence of POTASH is not accurately reflected by the paucity of reports of the condition in the medical literature. When a healthcare provider encounters an individual in whom the diagnosis of POTASH is being considered, the following should be performed: (I) a complete history to determine if the hand and finger swelling is asymptomatic and is associated with an ambulatory activity; and (II) a complete examination of the skin and mucous membranes to exclude angioedema and urticaria. It is crucial that clinicians are aware of ambulatory-related hand swelling so that they can diagnose POTASH and provide reassurance to affected patients who seek evaluation for the condition.

Acknowledgments

The author thanks the patient of this case report.

Funding: None.

Footnote

Reporting Checklist: The author has completed the CARE reporting checklist. Available at https://acr.amegroups.com/article/view/10.21037/acr-24-101/rc

Peer Review File: Available at https://acr.amegroups.com/article/view/10.21037/acr-24-101/prf

Conflicts of Interest: The author has completed the ICMJE uniform disclosure form (available at https://acr.amegroups.com/article/view/10.21037/acr-24-101/coif). The author has no conflicts of interest to declare.

Ethical Statement: The author is accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All procedures performed in this study were in accordance with the ethical standards of the institutional and /or national research committee(s) and with the Helsinki Declaration (as revised in 2013). Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Cohen PR. Post Ambulatory Swollen Hands (POTASH): An Autobiographical Case Report. Cureus 2021;13:e19312. [Crossref] [PubMed]
2. Cohen PR. Running associated swollen hands (RASH): case report of post ambulatory swollen hands (POTASH) in a man who completed a half marathon. Skinmed 2024; In Press.
3. Cohen PR. Post ambulatory swollen hands (POTASH) revisited: post ambulatory hand swelling in a half marathon participant. Dermatol Online J 2022; [Crossref] [PubMed]
4. Ravaglia FF, Leite MG, Bracellos TF, et al. Postambulatory hand swelling (big hand syndrome): prevalence, demographics, and association with dog walking. ISRN Rheumatol 2011;2011:659695. [Crossref] [PubMed]
5. DesMarais M. Swollen hands when hiking or walking-the complete explanation. Hiking and Fishing (August 11, 2021). Accessed: May 7, 2024. Available online: https://hikingandfishing.com/swollen-hands-when-hiking/
6. Cohen PR, Cohen BS, Kurzrock R. An Autobiographical Case Series of Familial Post Ambulatory Swollen Hands (POTASH): Hand Swelling in a Man and His Sister While Participating in a Half Marathon. Cureus 2024;16:e55518. [Crossref] [PubMed]
7. Cohen PR. Fist sign-associated post ambulatory swollen hands. JAAD Case Rep 2023;36:116-8. [Crossref] [PubMed]
8. Harada K, Hasegawa K, Otsuka F. Swollen Hands and "Fist Sign" in Acromegaly. Am J Med 2019;132:e618-e619. [Crossref] [PubMed]
9. Patel JR, Lewis DJ, Wei J, et al. Exuberant allergic contact dermatitis leading to hand compartment syndrome. JAAD Case Rep 2023;35:46-8. [Crossref] [PubMed]
10. Wang HN, Wu CY, Chen CB. Ichthyosiform Rashes and Joint Pain in a Boy. JAMA Dermatol 2021;157:1231-2. [Crossref] [PubMed]
11. Cohen PR. The positive fist sign: a clinical stigmata of Blau syndrome? JAMA Dermatol [Comment to: Ichthyosiform rashes and joint pain in a boy]. (November 15, 2021). Accessed: May 7, 2024. Available online: https://jamanetwork.com/journals/jamadermatology/fullarticle/2784047
12. Oak NR, Abrams RA. Compartment Syndrome of the Hand. Orthop Clin North Am 2016;47:609-16. [Crossref] [PubMed]
13. Jalan D, Garg B, Marimuthu K, et al. Giant lipoma: an unusual cause of carpal tunnel syndrome. Pan Afr Med J 2011;9:29. [Crossref] [PubMed]
14. Cohen PR. Injected Drug Addiction-Associated Swollen Hands: A Case Report of Methylamphetamine-Related Unilateral Drug Addiction-Related Puffy Hand Syndrome. Cureus 2024;16:e51545. [Crossref] [PubMed]
15. Joshi V, Green A, Griffin J. A case of bilateral swelling of the hands in an elderly gentleman. British Journal of Medical Practitioners 2009;2:44-5.
16. Jaros S, Googe P, Ziemer C, et al. Unusual clinical presentations of cutaneous squamous cell involving distal extremities in four patients: the importance of tissue sampling. Wounds 2023;35:E149-53. [Crossref] [PubMed]