Information has been received from the authors in a published literature article and refers to a 51-year-old female patient who presented with a necrotic ulcer at the site of recent diphtheria toxoid, pertussis acellular vaccine (unspecified), tetanus toxoid  (Tdap) and PNEUMOVAX vaccination. The patient received both vaccines in her right deltoid 10 days prior to presentation. She had no previous history of local or systemic vaccine reaction. On the evening of vaccination, the patient experienced tenderness, redness, and induration at the vaccination site. The next day bruising developed followed by blistering. A short course of oral doxycycline and a gluteal intramuscular steroid injection provided only mild transient relief. The blister ruptured on day 4, draining serosanguinous fluid. There was no purulent drainage, but redness persisted at the site. Over the following few days, the eroded blister progressed into a necrotic ulcer with black anesthetic eschar with a surrounding large tender ill-defined indurated erythematous plaque. The patient applied neomycin to the ulcerated area and covered with a bandage prior to presentation, but this did not provide any relief. At presentation, she was afebrile and had no leukocytosis. Wound and blood cultures returned negative at 48 hours. Punch biopsy for tissue culture and histological evaluation was performed. Tissue cultures were negative. Dermatopathology results showed nonspecific diffuse and extensive dermal and epidermal necrosis. There was mixed inflammatory cell infiltrate within the dermis with preservation of dermal collagen. Eccrine coils and hair follicles were necrotic. No definitive granulomas were identified. Periodic acid-Schiff, Fite, Gram, silver, and acid-fast stains did not reveal microorganisms. The patient was counseled to apply Vaseline and SILVADENE cream for wound care and ibuprofen as needed for pain. The outcome of the events was unknown. The authors stated that Adjuvants are common in vaccines and are added to optimize the immune response to antigens. Adjuvants are generally considered safe; however adverse events to adjuvant components can occur, especially when injected into subcutaneous fat rather than intramuscularly. Aluminum salts are commonly used adjuvants that have been associated with a variety of local adverse reactions including granuloma formation, allergic reaction, and myofasciitis. Patients with this local reaction present with mobile subcutaneous nodules. Histological patterns can vary and can include necrobiosis. While this reaction pattern was more common than previously suspected, it was still uncommon and the benefits of aluminum salt adjuvants are thought to outweigh the risks. Clinically necrotic and rapidly progressive severe local reactions to vaccines containing aluminum salts were very rare. Post-vaccination delayed hypersensitivity reaction to aluminum salts can result in injection site adverse reactions like erythema, subcutaneous nodules, and sterile abscess formation. Though the patient had frank necrosis rather than an itchy subcutaneous, a delayed type hypersensitivity reaction should be a consideration in the etiology of her ulcer. Improper placement and subsequent inflammatory reaction to aluminum salts was the likely cause of the patient's condition; however, allergic reaction to aluminum or other vaccine components should be considered. The Pneumovax vaccine contains the preservative pheno l, a potential allergen. Neomycin was a known contact allergen, and application at the ulcer site may have elicited a delayed-hypersensitivity; however, neomycin-induced granulomatous reaction had not previously been reported. It was also possible that this represented a hypersensitivity reaction to aluminum. However, even in aluminum-allergic patients, proper intramuscular injection reduces local adverse reactions and allows these patients to safely receive aluminum-adjuvant vaccines. Infection was thought to be unlikely given the patient's negative cultures, afebrile state, and normal leukocyte count. It was imperative that healthcare professionals recognize the importance of proper vaccine placement, needle size, and needle length in the placement of vaccines. Proper placement not only reduces adverse local reactions but also improve vaccine efficacy and patients trust in their health care provider. Proper intramuscular placement and appropriate needle size and length may prevent this severe vaccine reaction and improve patient outcomes. Upon internal review, Vaccination site necrosis was considered to be medically significant.