Factitial panniculitis - Skin
Mechanical causes – local pressure or repetitive blunt trauma
Physical causes – skin exposure to cold (eg, popsicle or ice cube), heat, or electricity (eg, site of electrode, electrostimulation, or electroacupuncture needles)
Chemical causes – syringe or needle injection of disparate materials such as the following, resulting in an inflammatory or foreign body reaction:
- Organic materials including acids, alkalis, milk, or microbiologically contaminated substances such as saliva, urine, or feces.
- Cosmetic materials intended to augment the size of breasts or genitalia, or reduce wrinkles. This includes products such as bovine collagen, polymethyl methacrylate microspheres, and polydimethylsiloxane as well as less commonly used materials such as paraffin (mineral oil) and vegetable oils (cottonseed, sesame, and camphor oil).
- Therapeutic agents including vitamin K, povidone, meperidine, pentazocine, gold salts, vaccines (eg, tetanus anti-toxoid), and glatiramer acetate (MS treatment). Extravasation of cytotoxic chemotherapeutic agents (eg, anthracyclines, vinca alkaloids, or taxanes) has also been documented.
The inflammation is self-limited with minimal systemic symptoms, unless there is sign of infection. In these cases, the patient may develop abscesses and lymphangitic spread if not treated. In cases of deliberate self-injury, the subcutaneous inflammation may appear resistant to treatment or chronically recurring. However, when the affected areas are covered with bandages or protective casts, there is a pronounced and rapid improvement.
The atypical distribution of the lesions will often suggest an exogenous origin. However, the wide range of possible causes and lack of reliable patient history make the diagnosis of FP difficult, sometimes requiring multiple admissions before the artificial nature of the lesions is discovered.
Related topics: Factitial dermatitis, Factitial ulcer
M79.3 – Panniculitis, unspecified
238884009 – Factitial panniculitis
- α1-Antitrypsin deficiency-associated panniculitis – Hereditary; decreased α1-antitrypsin levels and atypical pulmonary function test results.
- Erythema induratum (nodular vasculitis) – Tender erythematous or violaceous nodules usually found on posterior calves; Mycobacterium tuberculosis infection is a strongly associated trigger.
- Erythema nodosum – Tender erythematous or violaceous nodules usually found on the anterior shins; lesions typically symmetrical, non-ulcerating, and associated with an underlying disease or systemic illness.
- Lupus erythematous profundus (lupus panniculitis) – More common in adult women; look for multiple nodules / plaques on trunk, buttocks, and proximal extremities; resolved lesions have areas of scarring and atrophy; ANA positive in 70% of cases.
- Pancreatic panniculitis – Pancreatic lipolytic enzymes released into bloodstream secondary to pancreatitis; look for elevated serum amylase and lipase levels; focal calcification and "ghost adipocytes" on histology; patient severely ill.
- Polyarteritis nodosa – Subcutaneous nodules, purpura, livedo reticularis, and Raynaud phenomenon; biopsy reveals small- to medium-vessel vasculitis; classically P-ANCA (myeloperoxidase) titers positive.
- Post-steroidal panniculitis (see panniculitis) – Following rapid withdrawal of oral corticosteroids; rare.
- Pyoderma gangrenosum – Painful solitary nodules that form ulcers; usually purulent; pathergy: do not debride lesion.
- Subcutaneous panniculitis-like T-cell lymphoma – Atypical cells on biopsy, though high number of false negatives; B-symptoms (eg, fever, night sweats, and weight loss) common.
- Superficial thrombophlebitis – Tender erythematous nodules forming along the course of a vein in lower leg; biopsy reveals large subcutaneous vein with central thrombosis.
- Suppurative / chronic skin infections, including but not limited to – MRSA, Nocardia, Actinomyces, atypical mycobacterium, and Leishmania (Old World and New World); can present with skin nodules that ulcerate and express liquid material; tissue cultures and biopsy required to rule out and/or distinguish between skin infections.
- Systemic sclerosis – Physical exam findings and serology (anti-SCL 70, anti-centromere, and anti-RNA polymerase I or II antibodies).
- Weber-Christian disease – Diagnosis of exclusion for recurrent fever and malaise with painful subcutaneous nodules; typically women aged 30-70; lobular panniculitis on biopsy.