Painful lumps in the axilla
The location of these lesions and the odorous fluid that drained from them pointed to the diagnosis. The acne on the patient’s back was another clue.
The differential includes an array of common skin conditions
The differential diagnosis in this case included carbuncles, cysts, acne, and abscesses.
A furuncle or carbuncle can result from an infection of hair follicles that can manifest as individual (furuncle) or clusters of (carbuncle) red, painful boils. They form on parts of the skin where hair grows, including the face, neck, armpits, shoulders, and buttocks. They respond well to treatment with antibiotics and incision and drainage. They can be recurrent but usually don’t cluster together in apocrine-rich areas, as seen with HS.
Epidermal inclusion cysts are keratin-filled inclusion cysts with epithelial-lined cyst walls. The cysts are subcutaneous and occasionally more superficial. They can occur almost anywhere but are most often found on the back, scalp, neck, face, and chest. They are usually solitary; however, when there are multiple cysts, they are not linked by sinus tracts as found in HS.
Inflammatory acne lesions tend to form on the face, neck, back, chest, and shoulders, while HS lesions appear most often in apocrine-rich intertriginous areas.
Skin abscesses are local deep infections of the skin caused by bacterial pathogens. The most common agent is Staphylococcus aureus (frequently methicillin resistant). Injection drug use and immunosuppression are risk factors. Although bacteria do not cause HS lesions, bacteria can exacerbate HS through colonization.
Continue to: No lab test needed to diagnosis hidradenitis suppurativa
