Hidradenitis suppurativa misunderstood and underdiagnosed

Misconceptions about hidradenitis suppurativa (HS) prevent dermatologists and other clinicians from properly diagnosing and treating what one expert says is a “crippling disease.”

One of the misunderstandings about HS is that it’s rare, according to

Gregor Jemec, M.D., D.M.Sc., professor and chair of dermatology at Roskilde Hospital, Health Sciences Faculty, University of Copenhagen, Denmark, who chaired a section on hidradenitis suppurativa at the 2015 World Congress of Dermatology in Vancouver, Canada. 

“U.S. registry studies suggest [it is rare], while European population studies suggest it is not,” Dr. Jemec says. “It is like looking in hospital records for how many people suffer from the common cold in November. You are not likely to get the impression that it is particularly common.”

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HS prevalence in the Europe, including mild cases, is reported to be between 1 and 2 percent, according to Dr. Jemec. And most HS patients are young adults. 

Iben Marie Miller, M.D., Ph.D.The true prevalence of HS is challenging to estimate because the disease is misunderstood and underdiagnosed, according to Iben Marie Miller, M.D., Ph.D., a post doctorial scientist in the department of dermatology, Roskilde Hospital, Denmark. Dr. Miller, who presented on HS comorbidity and epidemiology at the World Congress, says HS prevalence varies from 0.5 percent to 4.1 percent, worldwide.

“Actually, Karl Marx was believed to have [had] HS but was also misdiagnosed when alive,” Dr. Miller says.

Among the other important misconceptions among doctors about HS are that it is a malodorous, or foul-smelling, disease with very few therapeutic options, according to Professor Errol Prens, M.D., Ph.D., who presented on immunological mechanisms underlying hidradenitis suppurativa at the World Congress. Dr. Prens, a dermatologist-immunologist at Erasmus University Medical Center of Rotterdam, The Netherlands, says it’s also a myth that these patients often become resistant to therapy.

NEXT: The science

The science

Errol Prens, M.D., Ph.D.While patients with HS often have a family history of the disease, the much stronger HS link is obesity, according to Dr. Jemec. 

“There is no convincing data that the quality of the diet plays a role, such as specific foods, but quite strong data that the quantity plays a role. Most patient have a high BMI, prevalence and diseases severity correlates with BMI and BMI reduction appears to induce remission,” Dr. Jemec says.

Smoking seems highly associated with the disease, according to Dr. Prens.

“Ninety percent [of HS patients] are active smokers or past smokers…,” Dr. Prens says.

Risk factors, comorbidities

According to Dr. Miller, the main comorbidities and risk factors in HS are: 

• Autoimmune diseases, such as Crohn’s disease 

• Diseases involving follicular occlusion, including acne 

• Malignancies such as squamous cell carcinoma 

• Psychological comorbidities, such as depression

• Smoking

• Metabolic syndrome, including obesity, hypertension, diabetes and dyslipidemia

 “Both the metabolic syndrome and smoking constitute cardiovascular risk factors, which is something HS has in common with psoriasis,” Dr. Miller says. “Preliminary data on body composition was presented demonstrating that HS patients not only have higher body mass index, but also higher fat percentage and lower muscle percentage compared to controls. This may suggest fat maldistribution, or perhaps even an altered metabolism altogether [may be a better description than BMI].”

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For many of these comorbidities, studies suggest and HS association, rather than cause, according to Dr. Miller. 

“The complexity of causality in many of these comorbidities are still to be explored. For example, we still do not know whether the association with metabolic syndrome is caused by HS or is due to confounders, such as lifestyle,” Dr. Miller says. “I also presented some cutting-edge additional preliminary results from Danish studies on HS suggesting that these patients may have a tendency of gallstones and renal hyperfiltration, which may be a sign of early renal damage.”¹

NEXT: Diagnosing HS

Diagnosing HS

The diagnostic criteria for HS have been clarified and are not complex, according to Dr. Jemec. The first is the characteristic element of inflamed or non-inflamed nodules, tunnels, abscesses and scars. The characteristic tomography of HS is on the axilla, inflammatory skin and groin. And the characteristic evolution of the disease, according to Dr. Jemec, is that it recurs and progresses to chronic disease.

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An important clue as to whether a patient has HS, according to Dr. Prens, is if the patient has had two episodes of boils in the axillae or groins in the past six months.

While the criteria may be simple, the diagnosis often eludes dermatologists and others, according to Dr. Miller. 

“A diagnostic delay of up to 12 years has been reported, maybe due to a mix of patients’ being reluctant to talk about their symptoms, as they feel embarrassed …, but also many doctors may not know the existence of this disease and mistake it for a common infection,” Dr. Miller says. 

NEXT: Evidence-based treatment

Evidence-based treatment 

Two of the most important steps HS patients can take to successfully treat the disease are to stop smoking and lose weight, according to the experts.

The current treatment algorithm for HS is in the European guidelines, published online January 30, 2015 in a supplement of the Journal of the European Academy of Dermatology and Venereology.²

“The European S1 HS guideline suggests that the disease should be treated based on its individual subjective impact and objective severity,” according to the guidelines. “Locally recurring lesions can be treated by classical surgery or laser techniques, whereas medical treatment either as monotherapy or in combination with radical surgery is more appropriate for widely spread lesions. Medical therapy may include antibiotics (clindamycin plus [rifampicin], tetracyclines), acitretin and biologics (adalimumab, infliximab).”

According to Dr. Prens, dermatologists treating mild HS should consider topical resorcinol 15% cream; topical clindamycin or oral tetracyclines. For moderate disease: topical resorcinol 15% cream; oral tetracyclines, rifampicin/clindamycin oral, acitretin oral; and, in some cases, biologics and surgical de-roofing. Severe disease treatments include: rifampicin/clindamycin oral, acitretin oral; biologic medications adalimumab or infliximab; surgical de-roofing and en bloc resection.

READ: Early results encouraging in study of adalimumab for hidradenitis suppurativa

HS treatments that are supported by the data, according to Dr. Jemec, include topical clindamycin 0.1% twice daily; tetracycline 500 mg twice daily; Nd: YAG laser; infliximab; and adalimumab. 

“Large cohorts further support the use of rifampicin 300 mg BID given with clindamycin 300mg BID, CO2 laser evaporation, de-roofing and surgery,” Dr. Jemec says. “Incision and drainage only works if fluctuating abscesses are found, which is not that common. In general, the patients need a broad approach combining medical and surgical therapy, pain management and appropriate bandages with support for patient self-management.”

Adalimumab [Humira, AbbVie], the first and only drug to have received FDA approval for the treatment of adults with moderate to severe HS. Adalimumab is the most documented drug for the disease, according to Dr. Jemec.³

“[Adalimumab] appears to have a clinically significant effect in moderate to severe cases, when given in the same dosage as used for the treatment of Crohn's disease,” Dr. Jemec says. “With the resurgent interest for this often crippling disease, a number of new treatments are being developed in academia, as well as by the industry. I am convinced that over the next ten years our ability to help the many patients more effectively will have improved greatly.”

References:

1. Miller IM, Carlson N, Mogensen UB, Ellervik C, Jemec GB. A Population- and Hospital-based Cross-sectional Study of Renal Function in Hidradenitis Suppurativa. Acta Derm Venereol. 2015 Feb 24. www.ncbi.nlm.nih.gov/pubmed/25710874

2. Zouboulis CC, Desai N, Emtestam L, Hunger RE, Ioannides D, Juhász I, Lapins J, Matusiak L, Prens EP, Revuz J, Schneider-Burrus S, Szepietowski JC, van der Zee HH, Jemec GB. European S1 guideline for the treatment of hidradenitis suppurativa/acne inversa. J Eur Acad Dermatol Venereol. 2015 Apr;29(4):619-44. Epub 2015 Jan 30. http://www.ncbi.nlm.nih.gov/pubmed/25640693

3. http://abbvie.mediaroom.com/2015-09-10-AbbVies-HUMIRA-Adalimumab-Receives-First-and-Only-U-S-Food-and-Drug-Administration-Approval-for-Moderate-to-Severe-Hidradenitis-Suppurativa 

Disclosures

Dr. Jemec: AbbVie, Actelion, Astra-Zeneca, Basilea, Celgene, Coloplast, Desitin, Jannsen-Cilag, Leo Pharma, Michelson Diagnostics, MSD, Novartis, Roche 

Dr. Miller:

Prof. Prens has received honoraria from AbbVie, Amgen, Baxter, Celgene, Eli Lilly, Galderma, Janssen-Cilag, Novartis and Pfizer for participating as a speaker, or in advisory boards. 

He received investigator-initiated grants that were paid to institution (Erasmus University Medical Center) from AbbVie, AstraZeneca, Janssen, NTRC and Pfizer.