Hidradenitis Suppurativa is an inflammatory skin disease of unknown cause. It has an autosomal dominant inheritance pattern, and androgen excess have been postulated. The disease is associated with Crohn disease and Dowling Degos disease.
Up to 4% of the general population are affected to some degree (see Hurley Stages below). There is a significant female preponderance
The disease affects areas bearing apocrine or sebaceous glands – groin, buttocks, inner thighs, axillae and under the breasts. Obesity aggravates the disease.
Hidradenitis suppurativa has three stages (Hurley Stages) 1:
- Solitary or multiple isolated abscess formation; no scarring or sinus tracts. Resembling acne
- Recurrent abscesses, single or multiple widely separated lesions. Sinus tract formation is present. This can restrict movement and incision and drainage may be required
- Diffuse or broad involvement across a regional area with multiple interconnected sinus tracts and abscesses. Fistulation and scarring.
The diagnosis of hidradenitis suppurativa is clinical, and imaging is nonspecific. MRI is the test of choice to assess extent and for complications. MRI is also useful to differentiate from Crohn disease 2, the main differential diagnosis.
STIR is considered the most useful sequence.
- marked thickening of the skin
- induration of the subcutaneous tissues
- formation of multiple subcutaneous abscesses
- prominent lymphadenopathy
The differential diagnosis for these findings includes carbuncles, lymphadenitis, and infected Bartholin's or sebaceous cysts. Sinus and fistula formation remote from rectum and anus (cf. Crohn disease) 3.
- focal intense FDG uptake in affected areas has been reported4
- 1. Hurley HJ. Axillary hyperhidrosis, apocrine bromhidrosis, hidradenitis suppurativa, and familial benign pemphigus: surgical approach. In: Roenigk RK, Roenigk HH, editors. Dermatologic surgery. Marcel Dekker, New York, 1989, pp. 729–739
- 2. N Griffin N, Taylor KM, Williams AB, S H Anderson SH, Irving PM, Sanderson JD, Desai N, Goh V. PWE-067 MRI to distinguish hidradenitis suppurativa from perianal Crohn's disease 2012;61:A324-A325 doi:10.1136/gutjnl-2012-302514d.67
- 3. Kelly AM, Cronin P. MRI features of hidradenitis suppurativa and review of the literature. AJR Am J Roentgenol. 2005;185 (5): 1201-4. doi:10.2214/AJR.04.1233 - Pubmed citation
- 4. Simpson RC, Dyer MJ, Entwisle J et-al. Positron emission tomography features of hidradenitis suppurativa. Br J Radiol. 2011;84 (1004): e164-5. doi:10.1259/bjr/74184796 - Free text at pubmed - Pubmed citation