Uncommon type of radiation dermatitis
Has a variable time course.
Difficult to get an appropriate history since many patients are not cognizant of past radiation exposure during fluoroscopy.
Radiation skin doses in fluoroscopy can range from less than one mGy/min to as high as several Gy/min In angiography cases.
Percutaneous coronary angiography for percutaneous coronary intervention is the most common cause.
Risk correlates with the length and complexity of the procedure.
Procedures associated include: radiofrequency catheter ablation, interventional neuroradiology, renal angioplasty, transjugular intrahepatic portosystemic shunt, and cardiac pacemaker placement.
Classified as acute, subacute and chronic presentations.
Patient can present with chronic FIRD without a preceding acute phase.
Acute radiation dermatitis presents 7-14 days after radiation exposure from doses in the range of two-5Gy.
Dermatologic manifestations include erythema, bullae, ulceration, epilation, and skin necrosis.
Differential diagnosis includes: herpes zoster, fixed drug eruption, cellulitis, immunobullous diseases, and a reaction to an arthropod or spider bite.
Treatment includes topical corticosteroids and barrier ointments such is petroleum jelly.
Chronic disease ranges from months to years characterized by telangiectasia, atrophy, sclerosis, itching, depigmentation, and also ulceration.
Rarely, may lead to a malignancy that may develop within the radiation field.
The minimum cumulatively dose for chronic diseases isb10-50 Gy.
Most commonly manifests in the anterior lateral area of the chest, mid back, lateral area of the trunk below the axilla, the scapula subscapular regions.
The rash may be associated with itching, pain, discoloration, and ulceration.
Histologically chronic disease includes dermal sclerosis, atypical fibroblasts,, telangiectasia, and absence of the hair follicles.
Treatment of chronic disease includes protection from sunlight, from further radiation, and the use of emollients.
For symptomatic patients topical steroids, analgesics or topical anesthetics can be utilized with excision, grafting, for both with complicated and refractory cases.