Case Report: Granulomatous Reaction Induced by Jellyfish Sting Causing Penis Deformity in a Child

A 10-year-old boy presented with genital irritation after an unknown sea sting, initially managed with analgesics. However, the inflammation persisted, and progressive penile deformity was observed, seemingly due to changes in the skin and prepuce (Figure 1A). Circumcision was performed but failed, as inflammation extended beyond the prepuce. In another hospital, it was suspected to be a vascular anomaly, leading to catheterization and selective embolization of the vascular area surrounding the penile skin. This treatment also failed to resolve the inflammation, which continued to progress. Subsequently, the child was taken to a pediatric hospital, where a biopsy was recommended. A biopsy was performed, revealing characteristics of chronic granulomatous inflammation. Based on these findings, and after failure of previous interventions including circumcision and vascular embolization, the treating physician prescribed topical tacrolimus 0.1% every 12 h. Tacrolimus was selected due to its immunosuppressive properties, which effectively reduce inflammation without causing skin atrophy, representing an advantage over corticosteroids. Following treatment, the patient demonstrated significant clinical improvement, with a marked reduction in inflammation and an overall enhancement of penile appearance (Figure 1B). The patient is currently awaiting further esthetic management for redundant penile skin. Microscopic analysis of the histological sections revealed squamous epithelium with a moderate chronic lymphocytic inflammatory infiltrate in the dermis. Epithelioid histiocytes were also observed, arranged in nodules forming granulomas, along with stromal fibrosis. No evidence of atypia or malignant neoplastic cells was found. (Figure 1C). This case highlights the rarity of granulomatous dermatitis secondary to jellyfish stings, a reaction with very little documentation in the literature. While most jellyfish stings cause acute reactions, delayed responses like granulomatous dermatitis are rare and challenging. Jellyfish stings are a common occurrence among ocean goers worldwide, with an estimated 150 million envenomations annually [1]. However, while most stings cause acute symptoms, chronic inflammatory responses such as granulomatous dermatitis remain exceedingly rare and poorly understood. Granulomatous dermatitis is characterized by the presence of granulomas with epithelioid cells and occasionally multinucleated giant cells, surrounded by a lymphocytic infiltrate. These granulomas represent a chronic response to the presence of antigens in the skin, typically due to a delayed hypersensitivity reaction [2]. The histological findings in this case align with previous reports describing lymphocyte infiltration and granuloma formation as typical manifestations of a chronic inflammatory response induced by jellyfish venom [3]. Immediate cutaneous reactions to jellyfish stings often include pain, erythema, and edema, whereas delayed reactions can evolve into granulomatous lesions or allergic contact dermatitis [3]. Tacrolimus is a calcineurin inhibitor that suppresses T-cell activation, reducing the production of pro-inflammatory cytokines such as TNF-α, making it useful in the treatment of chronic and granulomatous dermatitis [4]. It is a macrolide immunosuppressant initially isolated from Streptomyces tsukubaensis in 1987 [5]. Unlike corticosteroids, tacrolimus does not induce skin atrophy, making it a safer long-term option for inflammatory skin conditions. Tacrolimus acts by inhibiting T lymphocyte activation through suppression of interleukin-2 (IL-2) transcription, reducing immune responsiveness to foreign antigens. It is metabolized in the liver and excreted in bile [5]. In this case, its use was justified by the need to reduce inflammation and promote the resolution of the granulomatous lesion. In this patient, the development of granulomatous dermatitis several weeks after the jellyfish sting is consistent with an unusual, delayed response. In international literature, only a limited number of cases of this type have been reported. Limited data prevents standardized treatment; each case requires a tailored approach. E.G. and D.P. wrote the manuscript; M.R. designed the study and provided the figures; G.I. and H.R. provided technical support and conceptual advice. All authors read and approved of the final manuscript. The authors have nothing to report. The authors have nothing to report. Ethical approval for the publication of this case report, including clinical details and images, was granted by the corresponding institutional ethics committee. Written informed consent was obtained from the patient's legal guardians by the treating physician. The authors declare no conflicts of interest. The data supporting the findings of this study, including histological images and case details, are available upon reasonable request to the corresponding author.