Paintball Purpura: The Ball Sports-induced Targetoid Erythema (SITE) Sign Revisited

The ball sports-induced targetoid erythema (SITE) sign is a term that refers to annular erythematous lesions surrounding normal skin that occur after ball to skin contact. Associated purpura may be present or absent. A 19-year-old college student presented with multiple purpuric lesions of targetoid appearance. Additional history revealed that the lesions corresponded with the areas of ball contact during a paintball game. Similar lesions have been described in the participants of other sports, including floorball, ping pong, racquetball, and squash. When evaluating a patient with targetoid erythema with or without accompanying purpura, additional history of recent participation is an activity involving a high-velocity ball may be useful for establishing the diagnosis of the ball SITE sign.


Introduction
Dermatoses may be associated with ball sports. One condition that has been observed is the ball sports-induced targetoid erythema (SITE) sign. The lesion may occur in participants of sports in which the size of the ball is usually small and the velocity is high [1].
The ball SITE sign was previously described as sports purpura [2]. However, this is a misnomer since the lesions can also be ecchymotic or both purpuric and ecchymotic [1]. A man who developed several purpuric targetoid lesions following contact from paintballs with his skin is described, and the features of the ball SITE sign are reviewed.

Case Presentation
A 19-year-old college student presented for evaluation of multiple asymptomatic red, skin lesions. Cutaneous examination showed three purpuric lesions that had a targetoid appearance of ecchymosis with normal-appearing skin in the center on his left scapula, left anterior shoulder, and left chest ( Figure 1). Additional history revealed that the patient had participated in a paintball activity three days earlier. The location of his cutaneous lesions corresponded to the sites where the paintball had contacted his skin. Correlation of the history and clinical presentation established the diagnosis of paintball-associated ball SITE sign.
Follow-up examination one week later (which was 10 days after the causative event) showed partial spontaneous resolution of the purpuric lesions on the left scapula and left anterior shoulder. The left chest lesion had completely resolved.
c Nomenclature of ping pong-associated ball SITE sign includes ping pong patches.
d Nomenclature of racquetball-associated ball SITE sign includes annular erythematous (and occasionally purpuric) patches, annular lesion, and racquetball-associated targetoid erythema (RATE) sign.
e Nomenclature of squash-associated ball SITE sign includes annular erythematous (and occasionally purpuric) patches, annular lesion, and targetoid erythema associated with squash (TEAS) sign.
The weight of the ball can be as low as 2.5 grams for ping pong balls and as high as 58.5 grams for racquetballs. The weight for squash balls can be as high as 25 grams. In contrast, paintballs weigh approximately 3.3 grams [1,5,6,9,11].
The diameters of the balls also vary. Racquetballs, squash balls, and ping pong balls all have greater diameters of approximately 57 millimeters, 40 millimeters, and 39 millimeters, respectively. In contrast, the paintball has a much smaller diameter of only 17 millimeters [1,5,6,9,11].
The speed of the ball is usually fast. Paintballs have been observed to travel at 191 to 205 miles per hour. In contrast, the other balls travel slower than the paintballs. Ping pong balls travel at 100 miles per hour, whereas racquetballs (traveling 77 to 191 miles per hour) and squash balls (traveling greater than 150 miles per hour) often move faster [1,5,6,9,11].
Our patient developed the ball SITE sign following contact with his skin from paintballs. The ball SITE sign occurring in participants receiving skin impact from paintballs has been described previously ( The authors, in their review of sports-related dermatoses, mention their personal observations of paintball purpura presenting as a large purpuric patch at the location where the paintball fired from an air-powered gun impacted the skin. [4] Levsky and

Crowe, 2005
A 25-year-old woman had a mildly tender, non-blanching, erythematous ring-shaped lesion on the left forearm. Other people who had been in contact with the patient also had similar lesions on their extremities and/or trunk. [5] Aboutalebi and Stetson,

2005
A 14-year-old man and his 12-year-old brother presented with multiple lesions on the trunk following a paintball game on the prior weekend. The lesions appeared as annular purpuric patches located at the sites struck by the paintballs. [6] Hassan and Cohen, 2020 Comprehensive review of paintball associated ball SITE sign. A 19-year-old man with cutaneous lesions caused by impact with paintballs that occurred three days prior to his office visit. What is now referred to as paintball purpura was initially described as paint pellet purpura by Siegel in 1986 [8]. Subsequently, ball SITE sign associated with paintballs has been described as paintball purpura and paint pellet erythema. The patients ranged in age from 14 to 32 years [4][5][6][7][8]. The morphology of their lesions was either erythema, purpura, or both [4][5][6][7][8].
The differential diagnosis of ball SITE sign is described in Table 3 [12][13][14][15][16]. Although there are several clinical lesions that can mimic the morphology of the ball SITE sign, the associated history of trauma to the skin site from a high-velocity ball is helpful in establishing the diagnosis. Therefore, a biopsy is usually not necessary to confirm the diagnosis of the ball SITE sign.

Reference
Exogenous a [12] Infectious b [13] Medication related c [14] Miscellaneous d [15] Reactive erythema e [13,16]  The treatment of paintball purpura is symptomatic. They lesions typically resolve spontaneously as they did in our patient. Also, they often reoccur on new sites of skin contact when the individual again participates in the activity.

Conclusions
The term ball SITE sign was introduced to characterize lesions of targetoid erythema that present after high-velocity contact of ball to skin; these lesions occur in the setting of various sports, including paintball, ping pong, racquetball, and squash. The annular red ring of erythema may or may not concurrently present with purpura; our patient's lesions had purpura. Also, similar to our patient, the lesions typically resolve spontaneously; therefore, a proper history is necessary to establish the diagnosis and avoid additional evaluation or unnecessary treatment.

Additional Information Disclosures
Human subjects: Consent was obtained by all participants in this study.

Conflicts of interest:
In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: Philip R. Cohen declare(s) personal fees from ParaPRO. Dr. Cohen is a paid consultant of ParaPRO. . Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work.