A case of radiation-induced localized exacerbation of hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition associated with a significant social and medical cost. Patients with HS may require emergency department care and inpatient care, and a study found that these patients have greater health care utilization compared with those with psoriasis.1 The prevalence of HS in the United States has been reported as low as 0.05%2 and as high as 4%.3 It most commonly occurs in women with an average age of onset of 23 years.4 Its destructive nature can be quite debilitating, and treatment is seldom curative. The typical lesions include recurrent, painful nodules and abscesses in intertriginous areas that may form sinus tracts.5 The most common locations for HS lesions in women are the inframammary region and the groin, whereas for men they are the buttocks and the perineal area.4 HS is graded on severity based on the Hurley stages I to III. Numerous options have been investigated for the treatment of HS; however, most are ineffective in achieving complete remission. Treatment options are often chosen based on disease severity and impact of the disease on quality of life. Current treatment options include oral zinc supplementation; laser hair removal; carbon dioxide (CO2) laser ablation; oral antibiotics such as clindamycin plus rifampicin, dapsone, and tetracyclines; and surgical unroofing and more extensive surgical excision. Biologics and immunosuppressants are considered for more recalctrant and symptomatic patients with stage III disease.4 Recent research has also found that CO2 laser therapy has comparable recurrence rates to those of wide excision.6 We report the case of a female patient who had a flare of HS over the entire radiation site after treatment for ductal carcinoma in-situ (DCIS). Radiotherapy commonly causes acute skin toxicity, which may include erythema, edema, and desquamation7 but to date has not been linked to the development of HS. In the past, radiotherapy was actually used to treat early lesions of HS.4