Hidradenitis suppurativa (HS) is a long-term skin condition characterized by recurring boil-like lumps under the skin. It most commonly affects areas where the skin rubs together, such as the armpits, groin, and under the breasts. HS is estimated to affect around 1-4% of the population, but many cases may go undiagnosed or misdiagnosed due to lack of awareness of the condition.
What is HS?
HS occurs when the hair follicles become blocked and inflamed. Small lumps develop under the skin which can be painful and eventually rupture, leaking pus. This can lead to further inflammation and scarring. The exact cause of HS is unknown, but it is associated with smoking, obesity, and family history. HS often develops after puberty and symptoms tend to fluctuate over time, with flare-ups followed by periods of remission.
Signs and symptoms
The main signs and symptoms of HS include:
- Painful lumps under the skin, commonly in the armpits, groin, under the breasts, and buttocks
- Boils that enlarge, drain pus, heal, and then return
- Scarring and skin hardening in affected areas
- Blackheads and tracts (tunnels) under the skin
- Discharge with a foul odor from lesions
- Fatigue and fever during flare-ups
Symptoms can range from mild to debilitatingly severe. Many people with HS experience significant pain, restricted mobility, and emotional distress.
Why does misdiagnosis happen?
There are several reasons why HS is often misdiagnosed:
Lack of awareness
HS is not yet widely known or understood, even within the medical community. Many doctors may not think to test for it or recognize the symptoms. Dermatologists are the specialists most familiar with diagnosing HS, but patients often first present to their primary care physician or other providers like surgeons.
Overlap with other conditions
The lumps and boils associated with HS can resemble other skin conditions like acne, folliculitis, and skin infections. HS lesions are often mistaken for recurrent abscesses or cysts. The location of HS lesions in sensitive areas may also deter proper examination.
Variable symptoms
HS symptoms like pain, drainage, and scarring can fluctuate over time and differ between individuals. Milder cases may go unnoticed for years before advancing. Patients and doctors alike may attribute recurring symptoms to separate conditions rather than an underlying chronic disease.
Psychosocial factors
The locations affected by HS may discourage patients from seeking medical assessment. Delayed help-seeking can impede getting an accurate diagnosis. Perceived social stigma regarding HS of the groin, buttocks, and other areas may also prevent patients from communicating openly with providers.
How is HS diagnosed?
There are no definitive laboratory tests for HS. Diagnosis relies on clinical evaluation based on recognizing the characteristic signs and patterns of symptoms. Medical guidelines outline the following criteria for diagnosing HS:
- Typical lesions appearing as painful nodules, boils, abscesses, and scarring
- Involvement of armpits, groin, genitals, under the breasts, or buttocks
- Recurrence of lesions in the same areas
- Presence of lesions for more than 6 months
- No other overriding cause for symptoms identified
Other tests like bacterial culture of draining lesions may be done to rule out infection. Skin biopsy can help confirm HS but is not required for diagnosis. Tracking symptoms in a diary over time can aid assessment.
Staging
Doctors may stage the severity of HS based on the extent of skin involvement and scarring:
Stage | Description |
---|---|
Stage 1 | Single or minor localized lesions without scarring |
Stage 2 | Recurrent localized lesions with light scarring |
Stage 3 | Diffuse lesions with significant scarring |
Stage 4 | Entire skin areas diffusely involved with severe scarring |
Early diagnosis and treatment is important to try to control progression to higher stages.
What conditions is HS confused with?
Some common misdiagnoses for HS include:
Skin infections
Boils and abscesses caused by bacterial infection such as staph can resemble HS lesions. But HS produces chronic, recurrent lesions rather than isolated skin infections.
Acne vulgaris
Moderate to severe acne can have painful nodules and scarring that mimics HS. However, acne typically begins at puberty and occurs chiefly on the face, chest, and back rather than the flexural regions affected by HS.
Folliculitis
Inflammation of hair follicles caused by friction, shaving, or blockage can look similar to mild HS. But folliculitis generally causes small, itchy pustules rather than large, deep lesions.
Pilonidal cysts
These cysts near the tailbone may be confused with HS lesions in the buttock region. However, pilonidal cysts arise from ingrown hairs and are not chronic like HS.
Sebaceous cysts
Cysts filled with sebum from oil glands can form on skin surfaces. But they are typically solitary, smooth masses rather than the recurrent, rupturing lesions of HS.
What other conditions can accompany HS?
HS has been associated with several other health conditions, although more research is needed on these links. Known comorbidities include:
- Metabolic syndrome
- Type 2 diabetes
- Inflammatory bowel disease
- Polycystic ovary syndrome (PCOS)
- Obesity
- Depression and anxiety
The chronic pain and drainage from HS lesions can also lead to complications like cellulitis, anemia, and lymphedema. Addressing any coexisting medical issues is an important part of HS management.
What’s the impact of misdiagnosis?
Delayed or incorrect HS diagnosis can have significant consequences:
- Progression to more severe, painful symptoms
- Development of drainage, odor, and soiling that affects relationships and self-esteem
- Scarring and contractures that limit mobility and flexibility
- Repeated courses of antibiotics for presumed infection providing only temporary relief
- Unnecessary testing and procedures for mistaken conditions
- Psychological distress from living with undiagnosed chronic illness
Early diagnosis and specialist care is key to controlling HS before it can cause extensive damage. Misdiagnosis often means missing the window for optimal treatment response.
Diagnostic delay
Studies reveal HS patients endure an average delay of 7 years between symptom onset and diagnosis. Living with undiagnosed disease for years severely impacts quality of life and leads to worse outcomes.
Advanced disease
One study found two-thirds of HS patients already had moderate-to-severe disease at time of diagnosis. This indicates most were misdiagnosed earlier in their disease course when treatment could have been more effective.
How to get an accurate HS diagnosis
If you suspect you may have HS, these tips can help get an accurate diagnosis and appropriate care:
See a dermatologist
Make an appointment with a dermatologist who can recognize early HS based on a thorough skin exam and your medical history. Dermatologists specialize in diseases of the skin, hair, and nails.
Track your symptoms
Keep a record of your HS flares detailing when and where lesions occur, what they look like, any pain or drainage, and triggers like shaving or heat. Photos can also help doctors make an assessment.
Get other causes ruled out
Your doctor should evaluate for skin infections, cysts, and other possible causes through testing before attributing recurrent lesions to HS.
Ask about common comorbidities
If you also have metabolic conditions like diabetes or inflammatory bowel disease, mention these to your doctor as they can co-occur with HS.
Consider a second opinion
If you disagree with your diagnosis or treatment plan, seek a second opinion from another dermatology specialist to confirm whether you have HS.
Conclusion
Hidradenitis suppurativa remains widely underdiagnosed due to factors like provider unfamiliarity, patient embarrassment, and symptom variability. Many patients initially receive misdiagnoses like skin infection or cysts before obtaining an HS diagnosis. Delayed or missed diagnosis allows HS to progress unchecked, causing unnecessary suffering and scarring. Increased awareness and screening can help identify cases earlier when treatment is more effective. Patients concerned about recurrent boils and bumps in characteristic HS regions should persist in getting assessed to determine if they have this chronic skin condition.