Highlights on Clinical Picture of Psoriasis PROF DR DOAA MAHGOUB CAIRO UNIVERSITY 1
Chronic Plaque Psoriasis Symmetric distribution of sharply defined, erythematous, scaly plaques. The scalp, elbows, knees and presacrum are sites of predilection, as are the hands and feet. Plaques may persist for months to years at the same locations. Although the course of this disease is chronic, periods of complete remission do occur. Chronic Plaque Psoriasis Because the percentage of body surface area involved does not reflect the severity of the individual lesions with respect to erythema, induration and scaling, the Psoriasis Area and Severity Index (PASI) was formulated. A score for nail involvement has also been proposed, known as the Nail Psoriasis Severity Index (NAPSI), but it has not been widely utilized. 2
Psoriatic Plaques Symmetric Distribution 3
Childhood Psoriasis Palmoplantar Psoriasis 4
Genital Psoriasis Guttate psoriasis More in children & adolescents. Preceded by upper respiratory tract infection. Elevated antistreptolysin O titre indicating recent respiratory tract infection in more than 50 % of cases. 5
Guttate psoriasis Erythrodermic Psoriasis Characterized by generalized erythema and scaling. Gradual or acute onset. Although there are many causes of erythroderma clues to the diagnosis of psoriatic erythroderma include previous plaques in classic locations, characteristic nail changes, and facial sparing. 6
Erythrodermic Psoriasis Pustular Variants Generalized Pustular Psoriasis The infiltration of neutrophils dominates the histologic picture, while erythema and the appearance of sterile pustules dominate the clinical picture. Triggering factors include pregnancy, rapid tapering of corticosteroids (or other systemic therapies), hypocalcemia, infections. Generalized pustular psoriasis during pregnancy is also referred to as impetigo herpetiformis. 7
Patterns of Generalized Pustular Psoriasis I- Von Zumbusch pattern. This is a generalized eruption starting abruptly with erythema and pustulation. The skin is painful during this phase. The patient has a fever and feels ill. After several days, the pustules usually resolve and extensive scaling is observed. Von Zumbusch pattern 8
2- Annular pattern The eruption is characterized by annular lesions, consisting of erythema and scaling with pustulation at the advancing edge. The lesions enlarge by centrifugal expansion over a period of hours to days, while healing occurs centrally. Annular Psoriasis 9
3- Exanthematic type This is an acute eruption of small pustules, abruptly appearing and disappearing over a few days. It usually follows an infection or specific medications e.g. lithium. No systemic symptoms. Also referred to as acute generalized exanthematous pustulosis. 4- Localized pattern Sometimes pustules appear within or at the edge of existing psoriatic plaques. This can be seen during the unstable phase of chronic plaque psoriasis and following the application of irritants e.g. tars. 10
Localized Pustular Psoriasis Pustulosis of Palms & Soles Sterile pustules of palmoplantar surfaces admixed with yellow brown macules & scaly erythematous plaques. A minority of patients have chronic plaque psoriasis elsewhere. Unlike generalized pustular psoriasis, pustules remain localized to palms & soles with chronic course. 11
Pustulosis of Palms & Soles Acrodermatitis continua of Hallopeau Rare manifestation of psoriasis. Pustules at distal portion of fingers and toes. Followed by scaling and crusting. Pustules in nail bed and nail shedding may occur. 12
Acrodermatitis continua of Hallopeau Special Locations Scalp psoriasis One of the commonest sites of psoriasis. Discrete lesions in contrast to the less well defined lesions of seborrhoeic dermatitis. However it is not possible to differentiate the two diseases in most cases and sometimes they coexist. Lesions advance on periphery of face, retroauricular areas and upper neck. 13
Scalp Psoriasis Scalp Psoriasis 14
Pityriasis amiantacia Sometimes in scalp psoriasis, scales may have asbestos like appearance attached to scalp hair. Although it can be seen in seborrheic dermatitis, infected atopic dermatitis and tinea capitis, yet psoriasis is the commonest cause of pityriasis amiantacia. Flexural psoriasis Flexural lesions are characterized by shiny, pink to red, sharply demarcated thin plaques. There is much less scale than plaque psoriasis. Often a central fissure is seen. When flexural areas are the only sites of involvement, the term inverse psoriasis is sometimes used. 15
Flexural Psoriasis Oral mucosa Migratory annular erythematous lesions with hydrated white scales (annulus migrans). In patients with acrodermatitis continua of Hallopeau and generalized pustular psoriasis. Tongue is the commonest location. Clinical and pathological appearance similar to geographic tongue. 16
Nail psoriasis The fingernails are more often affected than the toenails. Patients with nail involvement appear to have an increased incidence of psoriatic arthritis. Psoriasis affects the nail matrix, nail bed and hyponychium. Nail Psoriasis Small parakeratotic foci in the proximal portion of the nail matrix lead to pits in the nails. Leukonychia and loss of transparency are due to involvement of the mid portion of the matrix. If the whole nail matrix is involved, a whitish, crumbly, poorly adherent nail is seen. 17
Nail Psoriasis Psoriatic changes of the nail bed result in the oil spot or oil drop phenomenon, which reflects exocytosis of leukocytes beneath the nail plate. Splinter hemorrhages are the result of increased capillary fragility, and subungual hyperkeratosis and distal onycholysis are due to parakeratosis of the distal nail bed. Nail Psoriasis 18
Psoriatic Arthritis Occur in 5 30 % of patients with cutaneous psoriasis. 10 15 % present with arthritis before appearance of skin lesions. Classification : 1- Mono & asymmetric oligoarthritis (commonest) 2- Arthritis of distal interpharyngeal joints 3- Rheumatoid arthritis like presentation 4- Arthritis mutilans (least common) 5- Spondylitis & sacroiliitis Disorders Related to Psoriasis Few disorders share important clinical and histological features with psoriasis. Distinct entities because they have different genetic, epidemiologic or clinical features. 19
I- Inflammatory linear verrucous epidermal nevus (ILVEN) ILVEN is characterized by linear psoriasiform lesions (i.e. scaling and erythematous plaques) that follow the lines of Blaschko. Based upon its chronicity and resistance to therapy, ILVEN is thought to be an entity separate from linear psoriasis. (ILVEN) 20
II- Reactive arthritis (Reiter s disease) This syndrome features urethritis, arthritis, ocular findings and oral ulcers, in addition to psoriasiform skin lesions. The lesions on the plantar surface usually have thick yellow scale and are often pustular (keratoderma blennorrhagicum). Psoriatic plaques on the penis are referred to as balanitis circinata Reactive arthritis (Reiter s disease) 21
III- Sneddon Wilkinson disease (subcorneal pustular dermatosis) This disorder is characterized by annular or polycyclic lesions, starting in the flexures. Very superficial (subcorneal) sterile pustules are the hallmark of Sneddon Wilkinso disease, hence its second name. There may be a gravity-induced demarcation in some vesiclopustules, with clear fluid superiorly and pus inferiorly. Its response to dapsone, combined with subcorneal pustules, provide support for this condition being a disease entity distinct from pustular psoriasis. Sneddon Wilkinson disease 22
Differential Diagnosis Plaques of psoriasis on shins may be misdiagnosed as lichen planus, but characteristic violaceous lesions elsewhere and mucosal involvement usually point to the correct diagnosis. Palmoplantar plaque psoriasis can be confused with keratotic eczema of the palms and soles, as both may have scaling and fissures. Sharp margination of the lesions favors psoriasis and examination of the remainder of the skin surface can differentiate both diseases. Differential Diagnosis Although seborrheic dermatitis is in the differential diagnosis of psoriasis, it is important to remember that it can coexist with psoriasis. Single or limited number of erythematous plaques, especially if they are treatment resistant, the possibility of SCC in situ (e.g. Bowen s disease, erythroplasia of Queyrat) needs to be excluded via histologic examination. 23
Differential Diagnosis Sometimes a biopsy is necessary to distinguish chronic plaque psoriasis from the mycosis fungoides. Clinical features suggestive of the latter include wrinkling due to epidermal atrophy and progression to infiltrated plaques. Dermatomyositis can involve the scalp, elbows and knees, as well as the hands, and initially may be diagnosed as psoriasis. Differential Diagnosis Other causes of erythroderma : Sézary syndrome, pityriasis rubra pilaris and drug reactions. In the case of guttate psoriasis, the differential diagnosis may include small plaque parapsoriasis, pityriasis lichenoides chronica, secondary syphilis and pityriasis rosea. The lesions of guttate psoriasis rarely involve the palms or soles and are often more erythematous than those of parapsoriasis. 24
Differential Diagnosis Psoriasis of the flexures is one cause of intertrigo. Other etiologies include seborrheic dermatitis, cutaneous candidiasis, tinea incognito, necrolytic migratory erythema, extramammary Paget s disease, Bowenoid papulosis and contact dermatitis. Differential Diagnosis In infants the possibility of Langerhans cell histiocytosis needs to be considered. In these patients, there may also be scalp involvement with scaling and crusts. Occasionally, tinea capitis is in the differential diagnosis of scalp psoriasis. 25
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