Psoriasis is a common chronic skin disorder typically characterized by erythematous papules and plaques with a silver scale, although other presentations occur. Most cases are not severe enough to affect general health and are treated in the outpatient setting. Rare life-threatening presentations can occur that require intensive inpatient management.

 

Classic lesion is a well-marginated, erythematous plaque with silvery-white surface scale. Distribution includes extensor surfaces (i.e., knees, elbows, and buttocks); may also involve palms and scalp (particularly anterior scalp margin). Associated findings include psoriatic arthritis (Chap. 163) and nail changes (onycholysis, pitting, or thickening of nail plate with accumulation of subungual debris).

 

NSAIDs, lithium, beta blockers, tumor necrosis factor (TNF) antagonists, interferon (IFN) α, and angiotensin-converting enzyme (ACE) inhibitors can exacerbate plaque psoriasis, whereas antimalarials and withdrawal of systemic glucocorticoids can worsen pustular psoriasis. The situation of TNF-α inhibitors is unusual, as this class of medications is used to treat psoriasis; however, they may induce psoriasis (especially palmoplantar) in patients being treated for other conditions.

Psoriasis is characterized by erythematous papules and plaques with a silver scale, although other presentations occur.

 

 


  • Maintain cutaneous hydration
  • Topical glucocorticoids;
  • topical vitamin D analogue (calcipotriol) and retinoid (tazarotene); UV light (PUVA, when UV used in combination with psoralens); for severe disease methotrexate or cyclosporine; acitretin can also be used but is teratogenic. Ustekinumab (human monoclonal antibody that blocks IL-12 and IL-23), apremilast (phosphodiesterase 4 inhibitor), secukinumab (anti IL-17), or ixekizumab (anti IL-17) can be considered for chronic, moderate to severe plaque psoriasis and are also approved for psoriatic arthritis. Guselkumab (anti IL-23) is approved for moderate to severe plaque psoriasis. Etanercept (dimeric fusion protein: TNF receptor/Fc human IgG1), infliximab, adalimumab, and certolizumab pegol (monoclonal antibodies directed against TNF) are approved for psoriasis and psoriatic arthritis.
  • Maintain cutaneous hydration;
  • topical glucocorticoids;
  • topical vitamin D analogue (calcipotriol) and retinoid (tazarotene);
  • UV light (PUVA, when UV used in combination with psoralens);
  • for severe disease methotrexate or cyclosporine;
  • acitretin can also be used but is teratogenic.
  • Ustekinumab (human monoclonal antibody that blocks IL-12 and IL-23) or apremilast (phosphodiesterase 4 inhibitor) can be considered for chronic, moderate to severe plaque psoriasis.
  • Etanercept (dimeric fusion protein: TNF receptor/Fc human IgG1), infliximab, and adalimumab (monoclonal antibodies directed against TNF) are approved for psoriasis and psoriatic arthritis.

 

 

 

 

Content 3

Content 13

A 25-year-old woman presents with a complaint of rash that has developed over the past several weeks and seems to be progressing. She describes the involved areas as mildly itchy. On examination, she is noted to have several plaque-like lesions over the extensor surfaces of both upper and lower extremities as well as similar lesions on her scalp. The plaques are erythematous with silvery scales and are sharply marginated.

What are the salient features of this patient's problem?

Progressive rash; mild itching; plaque-like lesions; extensor surfaces of extremities and scalp distribution; sharp margins with silvery scales

How do you think through her problem?

What are the common skin diseases in the differential diagnosis of this woman's eruption, and what features about her presentation make psoriasis the most likely diagnosis? (Candidiasis, tinea, and atopic dermatitis are characterized by poorly demarcated lesions and typically present on the extensor surfaces. Candida, in particular, is found in the moist body folds and flexural surfaces. This patient's lesions are described as mildly pruritic, which is more typical of psoriasis than these alternative diagnoses. The scaly scalp plaques are particularly characteristic of psoriasis.) How does her presentation differ from that of seborrheic dermatitis?What other manifestations should you explore? (Nail pitting is common in psoriasis and will help confirm your diagnosis. Joint pain and inflammation would raise the possibility of psoriatic arthritis.)

 

 

 


 

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