Foreign modelling agent reaction (FMAR) is a chronic inflammatory and granulomatous response to injected, non‑biodegradable substances used for cosmetic body contouring, such as mineral oil, silicone, or acrylates. It can present years after injection with painful induration, ulceration, and systemic complications, and often reaches specialized wound centers late.
FMAR has been described as an emerging epidemic in parts of Latin America, with case series from Mexico and Colombia reporting hundreds of affected patients over a decade and some centers seeing dozens of new cases per week. Typical injectors are non‑medical personnel using industrial‑grade oils or mixed substances for buttock, breast, or leg augmentation, frequently in women and in men who have sex with men.
For wound clinicians, FMAR matters because it mimics more familiar entities—infected pressure injuries, vasculitis, panniculitis, even malignancy—yet standard local care alone rarely controls the disease. The injected material migrates through subcutaneous planes and lymphatics, driving persistent granulomatous inflammation, recurrent infections, and difficult‑to‑heal ulcers.
Beyond local tissue damage, FMAR can trigger autoimmune/inflammatory phenomena and life‑threatening events such as fat‑like embolism and acute lung injury, described in several case reports and series available through open‑access literature (for example, Martínez‑Villarreal et al., 2016). Understanding this syndrome allows wound teams to recognise red flags early, avoid futile interventions, and route patients into multidisciplinary care pathways.
Foreign modelling agent reaction should be suspected in any patient with chronic indurated plaques, nodules, or ulcers in typical augmentation sites—especially buttocks, thighs, legs, breasts, or genitalia—when the clinical course seems out of proportion to usual etiologies and standard therapy.
History is critical. Patients may not volunteer cosmetic injections, particularly if procedures were illicit, low‑cost, or performed abroad. Ask neutrally about “any injections or fillers for shaping this area,” including “vitamins,” “collagen,” or “biopolymers.” Latency from injection to symptoms can range from weeks to over 10 years, so take a long timeline.
Common local findings include board‑like induration, erythema, alternating hyper‑ and hypopigmentation, nodules, and draining sinuses with oily or purulent material. Ulcers often have undermined borders over a woody, sclerotic base. Lesions can extend far beyond the original injection site due to gravitational or lymphatic migration of the material.
Basic workup starts with photography and careful mapping of all affected areas. Laboratory tests typically show elevated inflammatory markers (CRP, ESR) and may reveal leukocytosis or autoantibodies in some patients. Swab or tissue cultures help identify superimposed bacterial or atypical mycobacterial infection, which was documented in a minority of cases in large series.
Imaging refines the diagnosis and extent. MRI, when available, is highly informative: it demonstrates the volume, depth, and pattern of the foreign material and associated inflammation, guiding surgical planning. Where MRI access is limited, ultrasound can still reveal increased echogenicity and depth of subcutaneous involvement. A deep skin or soft‑tissue biopsy remains important to confirm granulomatous foreign body reaction and exclude malignancy.
Foreign modelling agent reaction ulcers require a dual approach: meticulous wound bed preparation and strategic control of the underlying inflammatory process. Without addressing both, recurrence and chronicity are the rule, not the exception.
At the wound level, standard principles apply: identify and debride non‑viable tissue using a modality tailored to pain, vascular status, and infection risk (surgical, mechanical, enzymatic, or biologic). Case series describe successful use of negative pressure wound therapy for large, exudative FMAR ulcers to promote granulation and reduce bioburden over weeks to months.
Topical dressings should maintain moisture balance while addressing contamination. Silver‑impregnated foams, polyhexanide gauze, or povidone‑iodine can be useful during high‑bioburden phases, followed by less cytotoxic options such as calcium alginate or modern super‑absorbent dressings as exudate decreases. Compression may be added cautiously on the lower extremities if arterial supply is adequate and pain is controlled.
Because injected material is diffusely intermixed with normal tissue, complete excision is often impossible. However, targeted surgical resection of dominant masses or chronically infected pockets—with flap or graft reconstruction—has improved outcomes in selected patients, especially for mammary or genital FMAR reported in reconstructive surgery literature (two‑stage reconstructions being one example).
Equally important is assembling a multidisciplinary team: dermatology, plastic or general surgery, infectious diseases, rheumatology, mental health, and rehabilitation. Patients frequently endure years of pain, disfigurement, and stigma; clear expectation‑setting—that disease control, not cure, is often the goal—can prevent disengagement from care when rapid improvement does not occur.
Foreign modelling agent reaction is not just a skin problem; it can involve lungs, liver, kidneys, musculoskeletal system, and the immune axis. Wound clinicians must recognise when a seemingly localized ulcer represents a systemic hazard requiring urgent escalation.
Red flags include unexplained dyspnea, cough, or hypoxia in any patient with a history of large‑volume injections. Case reports describe acute and delayed “silicone embolism” or fat‑like embolic syndromes after gluteal or breast injections, sometimes triggered by manipulation or incision and drainage procedures. Progressive respiratory symptoms in this context warrant immediate emergency referral, imaging, and specialist input.
Other concerning systemic features are persistent fevers, weight loss, arthralgias, Raynaud‑like episodes, or laboratory evidence of multi‑organ involvement (rising creatinine, abnormal liver function tests, cytopenias). Some FMAR patients meet proposed criteria for autoimmune/inflammatory syndromes induced by adjuvants, with autoantibody positivity and hypergammaglobulinemia reported in observational cohorts.
When systemic involvement is suspected, collaboration with rheumatology and internal medicine is essential. Published protocols from high‑volume Latin American centers describe stepwise use of oral corticosteroids (such as deflazacort) followed by immunomodulators including colchicine, azathioprine, hydroxychloroquine, or, in refractory cases, cyclophosphamide or TNF‑alpha inhibitors. These regimens require close monitoring and are generally beyond the remit of stand‑alone wound clinics.
For front‑line staff, the key actions are early recognition, thorough documentation, and timely referral rather than attempting to manage complex systemic FMAR in isolation.
Foreign modelling agent reaction carries heavy psychological and social burdens. Many patients feel shame about having sought low‑cost cosmetic enhancement, especially if done by unlicensed providers or outside the formal health system. Sensitive, non‑judgmental communication from the wound team is crucial.
Begin by validating the patient’s experience—acknowledging their pain, disfigurement, and fear of further loss of function or attractiveness. Clearly explain that the reaction is caused by the body’s response to the injected material, not by poor personal hygiene or non‑adherence. Use plain language to describe chronic inflammation and scarring, and why symptoms may flare episodically even with treatment.
Set realistic expectations about prognosis. Data from long‑term series show median latency of several years to symptom onset and protracted courses of care, often over multiple years. Complete removal of all material is rarely achievable; instead, goals include pain control, ulcer closure where possible, infection prevention, and maintaining mobility and body image.
It is also important to explore mental health impacts. Depression, anxiety, and body dysmorphic concerns are common but under‑reported. Establish relationships with behavioral health colleagues or community resources experienced in appearance‑related distress. When discussing reconstruction, emphasize functional priorities (sitting, walking, intimacy without pain) rather than purely aesthetic perfection.
Finally, encourage patients to avoid further injections or “touch‑ups,” which some may consider to camouflage deformities. Additional unregulated fillers almost always worsen disease activity and complicate future surgical options.
Foreign modelling agent reaction will likely remain under‑recognized unless wound services deliberately screen for it. Simple clinic‑level protocols can improve detection, documentation, and long‑term outcomes while generating data for quality improvement and research.
Start with standardized intake questions for all patients presenting with ulcers or chronic induration in high‑risk anatomical sites. Include prompts about cosmetic or body‑contouring injections, location and date, who performed the procedure, and what substance was reported. Normalizing these questions—asking everyone—reduces stigma and missed disclosures.
Next, create a structured documentation template capturing typical FMAR features: distribution of plaques/ulcers, degree of induration, color changes, presence of nodules or fistulas, pain scores, systemic symptoms, and prior interventions. Consistent photography at each visit allows objective comparison and can support surgical planning or external consultations.
Where possible, define referral thresholds to dermatology, surgery, rheumatology, and infectious disease based on red‑flag criteria (e.g., rapidly progressive induration, recurrent systemic infections, respiratory complaints). Embedding these triggers into electronic records or checklists helps frontline nurses and APPs escalate cases promptly.
Finally, consider participating in registries or institutional audits of FMAR cases, recording substances (when known), latency, complications, and outcomes. Published series from high‑volume centers demonstrate how such datasets can inform staging systems and treatment algorithms. Even small numbers from individual clinics add to the global understanding of this preventable, high‑impact cause of chronic wounds.