Leprosy and psoriasis both cause uncomfortable skin lesions and other similar symptoms. Despite their parallels, the conditions have different causes and treatments.

Leprosy, also known as Hansen’s disease, is best known as a skin infection of biblical proportions, thanks to multiple mentions of it in the Bible. It was devastating in ancient times, but it’s now rare and easily treated and cured in the United States.

Hansen’s disease is caused by Mycobacterium leprae, a slow-growing bacterium that cannot live outside its host. It’s difficult to study because it can only be grown in animals and the symptoms take years to develop.

Psoriasis, on the other hand, is an autoimmune disorder. It causes skin cells to grow rapidly, leading to skin lesions and plaques. Psoriasis isn’t contagious. A combination of genetics and environmental triggers is thought to cause psoriasis.

Hansen’s disease affects the skin, nerves, and muscles. The two forms of Hansen’s disease are lepromatous Hansen’s disease and tuberculoid Hansen’s disease . Lepromatous Hansen’s disease is the worse type. It causes both sores and large lumps on the skin.

Psoriasis also causes sores on the skin, but these usually look more like dry patches of skin. Sometimes psoriasis may cause your skin to crack and bleed. Symptoms range in severity.

Below is a comparison of the common symptoms of Hansen’s disease and psoriasis.

Hansen’s disease symptomsPsoriasis symptoms
Skin lesions or sores that may be discoloredRed-purple patches of skin with silvery scales
Skin growthsCracked skin that may bleed
Dry skinItching
Thick or stiff skinBurning
Severe painSoreness
Numbness in affected areasPitted, ridged, or thickened nails
Muscle weaknessStiff and swollen joints (psoriatic arthritis)
Eye problems, such as keratitis, iritis, or corneal ulcers
Enlarged nerves
Stuff nose and nosebleeds
Foot ulcers
Loss of sensation

Hansen’s disease is not highly contagious, but it may be spread person-to-person through nose and mouth droplets or possibly broken skin. According to the World Health Organization, global Hansen’s disease was eliminated in 2000. This means there’s less than one case per ten thousand people globally today.

Despite these gains, the Centers for Disease Control and Prevention indicates Hansen’s disease is still widespread in certain countries such as:

  • Angola
  • Brazil
  • India
  • Madagascar
  • Nepal
  • Central African Republic

Your risk of getting Hansen’s disease increases if you live in one of the previously listed countries or if you come into prolonged close contact with someone who has the infection. The risk is still low, however, since research indicates that 95 percent of humans are naturally immune.

Unlike Hansen’s disease , psoriasis isn’t contagious. The following factors put you at a higher risk of developing psoriasis:

  • a family history of psoriasis
  • HIV or a suppressed immune system
  • obesity
  • smoking
  • a significant amount of sustained stress

Hansen’s disease is treated with antibiotics over a period of six months to two years. Most people undergoing Hansen’s disease treatment continue their daily activities.

Psoriasis treatments focus on reducing symptoms, such as moisturizing skin, removing scales, calming redness, and controlling skin inflammation. Treatment options include:

  • over-the-counter topical medications
  • topical corticosteroids
  • anthralin
  • pine- or coal-tar products
  • light therapy, such as sunlight, ultraviolet A (UVA), ultraviolet B (UVB), psoralen plus ultraviolet A (PUVA), or excimer laser
  • immunomodulator drugs, such as Enbrel, Remicade, Humira, or Stelara

Hansen’s disease and psoriasis both cause skin lesions, but they’re very different diseases. Psoriasis is caused by a malfunction in your body’s immune system and isn’t contagious. Leprosy is caused by bacteria and is contagious.

To help you distinguish between Hansen’s disease and psoriasis, consider these differences:

Hansen’s diseasePsoriasis
Lesions typically don’t have flaking scales.Lesions may have flaking, silvery scales.
Lepromatous Hansen’s disease causes large lumps on the skin.Doesn’t cause skin lumps.
Pain tends to be more severe.Pain tends to be less severe.
May cause numbness around the affected area.Doesn’t cause numbness.
May lead to limb disfiguration.Doesn’t lead to limb disfiguration.
May cause a loss of pain sensation leading to broken bones, burns, or other injuries.Doesn’t cause a loss of pain sensation.
May cause muscle weakness.Doesn’t affect the muscles.

Any undiagnosed skin lesion that doesn’t heal on its own warrants a call to your doctor. Obtaining a correct diagnosis is always critical to getting the right treatment. In most cases, the earlier you understand your diagnosis and begin treatment, the better the outcome.

If you’ve been diagnosed with Hansen’s disease or psoriasis and your symptoms worsen or are not improving with treatment, or if you experience signs of infection, contact your doctor right away. The signs of infection may include:

  • fever
  • severe pain
  • nausea
  • vomiting

If you have Hansen’s disease and experience numbness or a loss of sensation in the affected body region, contact your doctor to discuss ways to prevent injury.