The many variants of psoriasis

Geographic tongue describes psoriasis of the tongue. The mucosa of the tongue has white plaques with a geographic border. Instead of scale, the moisture on the tongue causes areas of hyperkeratosis that appear white.

Nail psoriasis can manifest as nail pitting (FIGURE 6), oil staining, onycholysis (distal lifting of the nail), and subungual hyperkeratosis. Nail psoriasis is often quite distressing for patients and can be difficult to treat.

^{PHOTO COURTESY OF JEFFREY J. MILLER, MD, MBA, PENN STATE COLLEGE OF MEDICINE, AND BRYAN E. ANDERSON, MD, PENN STATE COLLEGE OF MEDICINE, DEPARTMENT OF DERMATOLOGY, PA}

Palmoplantar psoriasis (FIGUREs 7A and 7B) can be painful due to the involvement of the palms of the hands and soles of the feet. Lesions will either be similar to other psoriatic plaques with well-demarcated erythematous scaling lesions or involve thickening and scale without associated erythema.

^{PHOTOS COURTESY OF JEFFREY J. MILLER, MD, MBA, PENN STATE COLLEGE OF MEDICINE, AND BRYAN E. ANDERSON, MD, PENN STATE COLLEGE OF MEDICINE, DEPARTMENT OF DERMATOLOGY, PA}

Psoriatic arthritis can cause significant joint damage and disability. Most affected individuals with psoriatic arthritis have a history of preceding skin disease.¹² There are no specific lab tests for psoriasis; radiologic studies can show bulky syndesmophytes, central and marginal erosions, and periostitis. Patterns of joint involvement are variable. Psoriatic arthritis is more likely to affect the distal interphalangeal joints than rheumatoid arthritis and is more likely to affect the metacarpophalangeal joints than osteoarthritis.¹³

Nail psoriasis is often quite distressing for patients and can be difficult to treat.

Psoriatic arthritis often progresses insidiously and is commonly described as causing discomfort rather than acute pain. Enthesitis, inflammation at the site where tendons or ligaments insert into the bone, is often present. Joint destruction may lead to the telescoping “opera glass” digit (FIGURE 8).

^{PHOTO COURTESY OF JEFFREY J. MILLER, MD, MBA, PENN STATE COLLEGE OF MEDICINE, AND BRYAN E. ANDERSON, MD, PENN STATE COLLEGE OF MEDICINE, DEPARTMENT OF DERMATOLOGY, PA}

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