Psoriasis -Etiology, Clinical Features, Oral manifestations, Histopathology, treatment, Auspitz sign

"Fight psoriasis, not yourself" - CariDee English. Even celebrities like Kim Kardashian deal with psoriasis.
Psoriasis is characterized by erythematous plaques covered with silvery white scales. The most common type is plaque psoriasis, often found on the scalp, trunk, and limbs. Nails may also be pitted or thickened.
Common sites-
Psoriasis commonly affects the scalp, trunk, extensor surfaces of the extremities, and nails.
Etiology
The cause of psoriasis is unknown but it is an autoimmune disease mediated by T lymphocytes. It is linked to specific HLA antigens and genetic predisposition. Triggers include infections, stress, winter, and injury (Koebner’s phenomenon).
Skin Turnover Rate
Normal skin turnover rate is 23 days, but in psoriasis, it is reduced to 3-5 days.
Prevalence and Onset
Psoriasis affects 2-5% of the population, typically starting in the 2nd or 3rd decade of life and is more common in women.
Clinical Features
Psoriasis presents as small, sharply delineated, dry papules with a silvery scale, often coalescing into large plaques. Common sites include the scalp, elbows, knees, back, chest, face, and abdomen. It is usually asymptomatic but may cause itching and is persistent with periods of exacerbation and quiescence.
Seasonal Variation and Triggers
Psoriasis tends to worsen in winter and improve in summer due to UV light exposure. It can be triggered by stress and anxiety.
Psoriatic Arthritis
Approximately 11% of psoriasis patients develop psoriatic arthritis, which can involve the temporomandibular joint (TMJ).
Auspitz’s Sign
Auspitz’s Sign is characterized by tiny bleeding points when deep scales are removed.
Oral Manifestations
Oral manifestations of psoriasis are extremely rare, presenting as gray or yellowish-white plaques, small papillary lesions, or ulcerations. Oral lesion activity often parallels cutaneous lesion activity.
Histologic Features
Histologic features of psoriasis include:
Parakeratosis
Absence of Stratum Granulosum
Test tube-shaped rete ridges
Tortuous, dilated capillaries
Thinned epithelium over connective tissue papillae
Monroe’s abscesses
Mild lymphocytic and histiocytic infiltration
Treatment
Patients should be advised that psoriasis is incurable, chronic, and not contagious. Treatment for mild to moderate lesions includes topical corticosteroids, calcineurin inhibitors, coal tar derivatives, vitamin D analogues, and retinoids. Moderate to severe cases may require phototherapy or systemic treatments such as methotrexate, cyclosporine, or new biological agents like infliximab and etanercept.
Questions
What is Auspitz's sign?
What are Munro’s abscesses?
What type of rete ridges are seen in psoriasis?
a) Saw tooth
b) Drop shaped
c) Thin and regular
d) Test tube shaped (correct answer)
Diseases of the skin
Reference: Shafer's textbook of oral pathology,Neville