Abscess

My patient has painful pustules and nodules in her axillae.  How can I distinguish hidradenitis suppurativa (HS) from folliculitis or recurrent skin abscesses?

FA Manian MD, MPH, , , , , , , , , , , , , , , Leave a comment

A key differentiating factor between hidradenitis suppurativa (HS) and more common conditions such as folliculitis or recurrent abscesses is the location and recurrence pattern of the lesions. HS is clinically diagnosed based on the following typical lesion characteristics:

  • Morphology: open comedones, pustules, painful nodules, abscesses, sinus tracks and scarring; 
  • Distribution: intertriginous or apocrine gland-rich areas, such as the axillae, inframammary folds, lower abdomen/waist, gluteal cleft, groin and inner thighs; and
  • Frequency: recurrent lesions in the same locations, with at least two or more episodes in six months1,2

In contrast, folliculitis involves inflammation of the hair follicle and may present with pustules or boils; however, lesions are superficial, occur anywhere hair is present, and are not complicated by deep nodules, sinus tracks or scarring.2

Although recurrent abscesses may mimic HS, they are typically unilateral or asymmetric, fluctuant and caused by bacterial infection with positive wound cultures. In contrast, HS is frequently a symmetric, sterile inflammatory condition unless secondarily infected. Additionally, abscesses generally respond to incision and drainage and antibiotics and do not result in sinus tracks or scarring.2

Once you suspect HS, your management may be guided by its severity using the following disease stages (Hurley staging).

  • Mild disease (Hurley stage I): localized lesions without sinus tracks or scarring. Treat with antimicrobial washes (chlorhexidine) and topical antibiotics (clindamycin).3
  • Moderate disease (Hurley stage II): typical lesions in multiple locations with or without sinus tracks and scarring. Treat with antimicrobial washes, topical antibiotics, and systemic antibiotics (tetracyclines or clindamycin). Consider adding rifampin, metronidazole, or moxifloxacin in refractory cases.3
  • Severe disease (Hurley stage III): diffuse painful lesions with extensive sinus tracks and scarring. Requires dermatology referral for consideration of biologics (eg, adalimumab), laser, parenteral antibiotics and/or surgical interventions.3

Across all stages of severity, patients should be counseled on smoking cessation, weight loss, diet modification and appropriate pain management.4 Acute flares may be treated with warm compresses, tetracyclines, and intralesional steroids.3 Incision and drainage is reserved for severe, painful lesions as routine drainage could worsen tunneling.5

Bonus Pearl: Did you know the average diagnosis delay for HS is up to 10 years?2 Primary care physicians have a unique position in early recognition and treatment of this debilitating disease.

Contributed by Taylor Lynch, MD, Mercy Hospital-St. Louis, St. Louis, Missouri

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References:

  1. Wieczorek M, and Walecka I. Hidradenitis suppurativa – known and unknown disease. Reumatologia 2016: 56: 337-339. doi:10.5114/reum.2018.80709. https://pubmed.ncbi.nlm.nih.gov/30647478/.
  2. Snyder, CL, Chen XL, Porter ML. Obstacles to early diagnosis and treatment of hidradenitis suppurativa: Current Perspectives on Improving Clinical Management. Clin Cosm Invest Derm 2023;16:1833-1841. doi:10.2147/CCID.S301794. https://pmc.ncbi.nlm.nih.gov/articles/PMC10361090/.
  3. Alikhan A, Sayed C, Alavi A, et al. North American clinical management guidelines for hidradenitis suppurativa: A publication from the United States and Canadian Hidradenitis Suppurativa Foundations: Part II: Topical, intralesional, and systemic medical management. J Am Acad Derm 2019;81:91-101. doi:10.1016/j.jaad.2019.02.068. https://pubmed.ncbi.nlm.nih.gov/30872149/.
  4. Hermak S, and Lev-Tov H. Integrative approaches in the management of hidradenitis suppurativa. J Am Acad Derm 2024;91: S42-S45. doi:10.1016/j.jaad.2024.09.016. https://pubmed.ncbi.nlm.nih.gov/39626999/.
  5. Chawla S, Toale C, Morris M, et al. Surgical management of hidradenitis suppurativa: A narrative review. J Clin Aesth Derm 2022;15: 35-41. https://pubmed.ncbi.nlm.nih.gov/35309275/.

Disclosures/Disclaimers: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy Hospital-St. Louis, Massachusetts General Hospital, Harvard Catalyst, Harvard University, their affiliate academic healthcare centers, or its contributors. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

My patient has painful pustules and nodules in her axillae.  How can I distinguish hidradenitis suppurativa (HS) from folliculitis or recurrent skin abscesses?

My elderly patient has a WBC count of 60,000 without obvious hematologic malignancy.  How likely is it that his leukocytosis is related to an infection?

FA Manian MD, MPH, , , , , , , , , , , , , , , , , , , , , , , , , Leave a comment

Although extremely high WBC count in the absence of myeloproliferative disease may be associated with solid tumors and other causes, infections are often the most common cause of leukemoid reaction (LR), including tuberculosis, Clostridiodes difficile colitis, shigellosis, salmonellosis, pneumonia, abscesses, as well as  parasitic infections (eg, malaria), fungal infections (mucormycosis), and viral diseases (eg, HIV, EBV, Chickungunya fever).1-4   

In a study of 173 hospitalized patients (mean age 69 y) with leukemoid reaction (defined in this study as WBC ≥30,000/µl), infection was the most common cause of LR (48%), followed by tissue ischemia/stress (28%), inflammation (eg, pancreatitis, diverticulitis without perforation) and obstetric diagnoses (7% each) and malignant tumor (5%).1 

In the same study, the most common infections were “sepsis”, pneumonia and urinary tract infections.  Bacteremia was documented in 13%, while Clostridiodes difficile toxin assay was positive in 7% of patients.  The highest WBC counts were observed in patients with either a positive blood culture or positive C. difficile toxin.  In-hospital mortality rate was very high at 62%.

Similarly, in a study involving 105 hospitalized patients, the most common cause was infection, followed by malignancy and other causes. 2 In a smaller study of 25 patients with “extreme” leukocytosis (defined as WBC ≥50,000/µl) infection was considered the cause in 52% and malignancy in 44% of patients; about one-third were bacteremic (eg, Pseudomonas sp, Streptococcus pneumoniae, E. coli).3

Bonus Pearl: Did you know that besides infections and malignancy, drugs (eg, corticosteroids, epinephrine) and ingestion of ethylene glycol have also been associated with LR? 1,3,4

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References

  1. Potasman I, Grupper M. Leukemoid reaction:Spectrum and prognosis of 173 adult patients. Clin Infect Dis 2013;57:e177-81. https://pubmed.ncbi.nlm.nih.gov/23994818/
  2. Portich JP, Faulhaber GAM. Leudemoid reaction: A 21st-century study. https://pubmed.ncbi.nlm.nih.gov/31765058/
  3. Halkes CJM, Dijstelbloem HM, Eelman Rooda SJ, et al. Extreme leucocytosis: not always leukaemia. The Netherlands J Med 2007;65:248-51. https://pubmed.ncbi.nlm.nih.gov/17656811/
  4. Kumar P, Charaniya R, Sahoo R, et al. Leukemoid reaction in Chickungunya fever. J Clin Diagn Res 2016;10:OD05-OD06. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4948452/

 

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy Hospital-St. Louis or its affiliate healthcare centers. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

My elderly patient has a WBC count of 60,000 without obvious hematologic malignancy.  How likely is it that his leukocytosis is related to an infection?