Postictal Petechial Skin Rash (Trout Skin) After a First Epileptic Seizure in a 54-Year-Old Man

Introduction

Epileptic seizure is an important cause of transient loss of consciousness (TLOC), accounting for up to 2% of all emergency department visits [1]. Distinguishing epileptic seizures from other forms of TLOC, such as syncope or psychogenic nonepileptic seizures, is challenging because there are no unique clinical features [2]. In this context, recognizing suggestive clinical signs can be helpful. Whereas lateral tongue biting and postictal confusion are well known signs [3], there is little awareness of thoracocervicofacial petechiae indicative of a convulsive epileptic seizure.

Petechiae are defined as pinhead-sized (less than 2 mm), reddish-purple spots on the skin or mucous membranes caused by bleeding into the dermis. Key pathophysiological mechanisms underlying the development of petechiae include disruption of vascular integrity (eg, leukocytoclastic vasculitis), thrombocytopenia, and platelet dysfunction disorders [4]. The localization of the petechial rash can help narrow the differential diagnosis. For example, thoracocervicofacial involvement may suggest a mechanical origin, such as a tonic-clonic seizure [5]. Although this sign is considered clinically distinctive and diagnostically valuable, it is rarely recognized or actively sought in clinical practice. To date, few case reports have described this finding, and significant gaps remain in the literature regarding the recognition and understanding of such localized petechial rashes in the context of epileptic seizures [5–9]. Increased awareness of this sign could facilitate the earlier identification of seizure-related events, particularly in cases where the clinical presentation is ambiguous or unwitnessed. This report describes the case of a 54-year-old man with a postictal petechial skin rash (trout skin) following a first epileptic seizure.

Case Report

A 54-year-old, previously healthy man presented to our Emergency Department after a first episode of loss of consciousness. His wife reported a loud scream and subsequent unconsciousness with trembling arms and legs, followed by confusion persisting for about 30 minutes. The patient’s history was unremarkable, without any recent illness or trauma, coagulation disorders, or bleeding tendency. Substance use, sleep deprivation, allergies, and medication or supplement intake were denied.

On arrival to the hospital, the patient was hemodynamically stable and afebrile. Neurological assessment showed a slight disorientation with retrograde amnesia to the event, but no focal neurological deficits were present. Physical examination revealed a lateral tongue bite and a sharply demarcated petechial rash over the shoulders, neck, and face (Figire 1A–1C) without itching or pain. Skin biopsies were not performed. Laboratory analyses showed mildly elevated serum levels of creatine kinase (346 U/L, normal range <190 U/L), but was otherwise normal without signs of inflammation (CRP 0.9 mg/L, normal range <5 mg/L), thrombocytopenia (thrombocytes 254G/L, normal range 150–370 G/L), or coagulopathy (INR 0.93, normal range 0.85–1.15).

The semiology described by the patient’s wife, the postictal state on arrival to the hospital, the lateral tongue bite, and the elevation of creatine kinase levels [10] suggested a first episode of an epileptic seizure. The pathognomonic petechial rash supported the diagnosis. CT and MRI of the head showed no intracranial mass, ischemia, or sinus vein thrombosis. Electroencephalographic studies were normal, with no evidence of interictal epileptiform discharges.

Antiepileptic therapy with levetiracetam (500 mg twice daily) was started. The petechial rash resolved spontaneously within 2 days. After an uneventful course, the patient was subsequently discharged. During the following 3 months, there were no further epileptic events, and the follow-up electroencephalographic studies were still normal, so we could initiate a tapering of the medication under EEG control.

Discussion

This case report highlights that, in the context of a TLOC, the presence of a localized thoracocervicofacial petechial rash may serve as an important clinical indicator suggestive of an underlying epileptic seizure.

Epileptic seizures account for 5–10% of all cases of TLOC [11], and are a common clinical problem, requiring prompt diagnosis to establish appropriate care and treatment. A thorough medical history-taking and physical examination are essential for diagnosis, but differentiating them from syncope, especially the convulsive form, is challenging. Even when witnesses provide an accurate description of the presumed seizure, diagnosis often relies on identifying specific accompanying symptoms. Some associated signs, such as convulsions or urinary incontinence, have no diagnostic value [12]. Conversely, lateral tongue biting and postictal confusion are well-recognized sequelae of generalized seizures [3].

Postictal petechial rash, also known as trout skin, is an underappreciated indicator of an epileptic etiology that commonly manifests on the face, shoulders, and neck. Notably, this rash may be the only objective sign present at the time of initial evaluation following a TLOC [6,7,11]. The distribution of the rash can provide insight into the etiology, as previously described [5–9]. Localized thoracocervicofacial manifestations suggest a mechanical origin. An acute and severe increase in intrathoracic pressure can lead to blood congestion and the rupture of thin-walled capillaries in the neck and face. Consecutive extravasation of erythrocytes manifests as petechiae and subconjunctival hemorrhages. Examples of this mechanism include persistent coughing, vomiting, and traumatic asphyxia [5,13]. The underlying pathophysiology behind this has not been conclusively defined. However, it is reasonable to assume that intrathoracic pressure increases significantly during a tonic-clonic seizure due to muscle activity. This leads to capillary disruption, which is the main contributor to postictal petechial skin rash and its characteristic distribution pattern. In addition to the ictal Valsalva maneuver, seizure-induced alterations in cytokines and vasoactive mediators are assumed to contribute to modifications in platelet function and capillary integrity, thereby promoting the development of petechiae [5,7]. Because the petechial rash resembles the speckled pattern of fish skin, this clinical sign is called the “trout phenomenon” (Figure 1D), as named by the French internist Armand Trousseau. The petechiae usually disappear completely within 48 hours to 2 weeks without further treatment [5,7,13]. Several case reports in the literature describe the thoracocervicofacial rash in the context of epileptic seizures [5–9]. The true incidence is unknown because systematic studies are lacking. However, this phenomenon appears to be an underrecognized clinical sign associated with epileptic seizures.

Conclusions

As a potentially alarming sign of a serious systemic disease, petechiae often prompt extensive diagnostic investigations. Recognizing petechiae with a specific pattern and excluding infection or a bleeding disorder can help avoid unnecessary testing and investigations when attributing them to an epileptic seizure. When diagnosing generalized seizures, physicians should examine patients for this rash, as it is a highly suggestive feature of epileptic seizures in the appropriate clinical context. This can contribute to a prompt diagnosis and immediate initiation of antiepileptic therapy.