The microbiology culture was negative. Histology revealed multiple empty cystic areas in the dermis and hypodermis, surrounded by an inflammatory histiocyte infiltrate. The study also revealed abundant foam cells and multinucleate giant cells (Fig. 3).

When questioned again, the patient admitted that he had undergone injections with mineral oil 2 years earlier in the buttocks on up to 30 occasions, for esthetic purposes. A year later, he began to present the symptoms described above. In light of this information, foreign body granuloma was diagnosed and treatment with 40mg per day of prednisone was prescribed; a complete clinical response was achieved. The patient was then discharged with a descending dose of prednisone over 2 weeks. Because he continued to present intermittent episodes, minocycline was prescribed at a dosage of 100mg per day, with no clinical improvement. Alopurinol was later prescribed but was poorly tolerated by the patient and it was therefore decided to change to 400mg per day of hydroxychloroquine; however, the episodes persisted. The patient has since been undergoing intermittent pulse corticosteroid therapy with prednisone and has remained asymptomatic.

The popularity of injectable fillers has increased markedly in recent decades. The materials used include a wide variety of nonauthorized products.1,2 Mineral oil (petrolatum) has been used for cosmetic purposes to perform injections of permanent dermal filler. This filler has even been used to increase muscle volume3 and penis size.2,4 The cosmetic results immediately after injections of petrolatum tend to be satisfactory; however, the long-term complications are disastrous. For this reason, petrolatum is not currently considered legal for use as a filler. Furthermore, it is not generally administered by medical personnel and is most frequently self-injected.3,4

The adverse effects of injections of fillers include arterial occlusion, tissue necrosis, embolism, infections, hypersensitivity reactions, migration of the injected material, and even death.5 The formation of sclerosing lipogranuloma or paraffinoma, a granulomatous reaction associated with intense fibrosis, is a frequent complication secondary to injection of mineral oil.2,4 Histology often shows a “Swiss cheese” image, owing to cystic spaces that replace the normal subcutaneous cell tissue.5

Complications following the injection of liquid chemical products will present in a period of time that may vary from months to years.1 Adverse effects, such as infection and ulceration, are often seen within 18.5 months after the paraffin injections.6 With regard to treatment, complete surgical excision is the best option for preventing recurrence3; however, complete excision is often not possible. Macrolides and tetracyclines have been shown to produce good results where infection is suspected, partly owing to their anti-inflammatory action.5 Oral or intralesional corticosteroids can be used to reduce granulomatous immune reactions.1,5 Other therapeutic alternatives include tacrolimus, etanercept, and alopurinol.1

Although most medical professionals no longer inject unauthorized products, unqualified personnel continue to expose themselves and third parties to severe complications. It is therefore very important to take this entity into consideration as a possible diagnosis, as most patients will be reluctant to admit to having undergone these procedures. It should also be remembered that the adverse effects caused by injecting this material may appear after a long period of latency.