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الكلية كلية الطب
القسم الباطنية
المرحلة 5
أستاذ المادة زينة سعيد سلمان الفاضلي
4/24/2011 7:18:57 PM
Lichen planus
Definition: lichen planus (LP) is a common, pruritic, inflammatory disease of the skin & mucous membranes. It occurs throughout the world, in both sexes & in all races, mostly in the age of 30-60 years, it is rare in children less than 5years.
Etiology & pathology: The etiology of LP is unknown, it may be familial in
1-2% (genetic), liver diseases; like: chronic active hepatitis and hepatitis-C are risk factors for LP (16% of patients with lichen planus had hepatitis-C infection). Drugs can cause LP; like: gold, mercury, chloroquine, penicillamine (lichenoid drug eruption). LP is characterized by an immunological reaction mediated by T-cells that result in keratinocytes apoptosis (death). Clumps of IgM, and less commonly IgG, IgA &C3 are present in the subepidermal zone with heavy inflammatory infiltrate.
Clinical features: The morphology & distribution of the lesions are characteristic. The primary lesions of LP are characteristic, almost pathognomonic, small, violaceous, flat-topped, polygonal papules. They can be remembered by learning the 5Ps (pruritic, plain, polygonal, purple papules). The surface of the lesions is glistening, dry & covered with scant scales & with close inspection a lacy, criss-crossed white lines can be seen (Wickham s striae). Papules are coalescing to form plagues. Site of predilection for LP is the flexor surfaces of the wrists & forearms, trunk, medial thighs, legs & genitalia. Pruritus is often prominent, it may be intolerable in acute cases, usually in a form of rubbing rather than scratching so scratch marks are not present. Koebner s phenomena can occur in LP. Lesions of LP usually heal with hyperpigmentation.
Involvement of genitalia is common. On the glans penis, lesions are flat papules or annular in shape, while on the vulvovaginal area ulcerative lesions are common & may coexist with the whitish reticulate classical lesions.
Oral involvement in LP occurs in over 50% of cases (some times without skin lesions), it appears as reticulate white patch mostly on the buccal mucosa, but it could be atrophic or erosive (ulcerative type). Oral lesions may be asymptomatic or have a burning sensation, or they may even be painful if ulcers are present.
Nail involvement are present in 5-10% of patients & includes: longitudinal ridging & splitting, onycholysis, red lunula, pitting, nail dystrophy, pterygium formation
(The proximal nail fold fuses with the proximal part of the nail bed due to inflammation & fibrosis of the nail matrix).
Clinical variant of LP include:
1. Linear LP: a type of LP in which the lesions are limited to one band or streak or single dermatome. It is more common in children & represents about 1% of cases of LP. Linear lesions also occur in classical LP due to Koebner s phenomena.
2. Annular LP: small papules are configurate to rings or circular plagues. This type is usually asymptomatic & favors the axillae, groin & genitalia. It is most common in males.
3. Hypertrophic LP: the typical lesions are verrucous plagues with variable amount of scales & it is usually larger than the classical lesions of LP (several centimeters in diameter). The favored site is distal extremities. It is chronic severely pruritic lesion & refractory to topical treatment.
4. Ulcerative LP: this type is rare on the skin but common on the mucous membranes like oral mucosa & vulvovaginal mucosa where it cause pain & burning sensation. The lesion consists of erythematous eroded area surrounded by white reticulation. This type carries a risk for squamous cell carcinoma about 0.5-5% of all patients & demands a biopsy in chronic lesions.
5. Bullous LP: in classical LP, sometimes lesions may vesiculate centrally due to subepidermal separation as a result of the inflammatory process. This usually occurs on the lower extremities & heals spontaneously.
6. Follicular LP: manifested as pinpoint hyperkeratotic, follicular projections in hairy areas specially the scalp. Hair loss occurs & it may be permanent if the disease is sufficiently active to cause scarring (LP is one of the commonest causes of scarring alopecia in Iraq). 70-80% of cases occurs in women.
7. Generalized LP: LP may occur abruptly as a generalized intensely pruritic eruption. Papules are numerous & isolated & leave diffuse brown postinflammatory hyperpigmentation as the disease clear. Lesions appear on the trunk, extremities & lower back. Lichenoid drug eruptions are frequently of this type.
8. Actinic Lp: is a variant of lichen planus that is more common in Middle Eastern countries in spring and summer, where sunlight appears to have a precipitating effect, it affects exposed areas of the face, dorsal hands and arms, and nape of the neck as macules & papules that are hyperpigmented and violaceous-brown in color.
Diagnosis: The diagnosis can be made clinically, but a skin biopsy can be done in difficult cases. Direct immunofluorescence may help to establish the diagnosis. There will be deposits of IgG, IgM, IgA & complement in the subepidermal zone.
Treatment:
1. Topical steroids: super potent class I&II steroids can be applies topically twice daily in a form of ointment or creams used for localized lesions.
2. Intralesional steroid: injection with triamcinolone acetonide may be used in hypertrophic lesions which are resistant to topical treatment. Injection done every 3-4 weeks.
3. systemic steroid: can be used to treat generalized severely pruritic LP prednisolone in a dose of 20 mg twice daily for 2-4 weeks is usually sufficient to clear the disease.
4. Antihistamines: should be given to relief pruritus.
5. Cyclosporine, acitretin (oral retinoid), azothioprine: all can be used with variable effect to treat generalized symptomatic LP or cases refractory to therapy with the above agents.
6. Phototherapy: like PUVA, narrow band UVB & UVA1 may be effective for cutaneous LP.
7. Oral LP can be treated with tacrolimus ointment 0.1%, topical steroid & oral cyclosporine as mouthwash beside other treatments if not responding to topical agents.
Prognosis: the natural history of LP is highly variable & dependent on the site of involvement & the clinical pattern. Two third of patients with skin lesions will have LP for less than 1 year & many patients spontaneously clear in the second year. Recurrences are common. Mucous membrane disease is much more chronic.
Pityriasis Rosea
Definition & etiology:Pityriasis rosea is an acute, self-limiting disease, probably infective in origin, affecting mainly children and young adults, and characterized by a distinctive skin eruption and minimal constitutional symptoms. Pityriasis rosea is relatively common throughout the world. It accounts for 1-2% of new patients attending dermatological clinics in temperate regions, where it is more frequent during the winter months. The cause of Pityriasis rosea is unknown, but many epidemiological and clinical features suggest that an infective viral agent may be implicated (HHV-6 & HHV-7). It is not contagious although small epidemics can occur.
Clinical features:The eruption of pityriasis rosea follows a distinctive and remarkably constant pattern and course in 80% of cases. The disease most frequently begins with the appearance of a single herald patch (mother patch) which is oval plague, pink-red in color & larger than succeeding lesions (2-10cm). The plague is covered by fine wrinkled scales arranged at its periphery called collarette scale. The plague persist for 1-2 weeks before the remaining rash appears which is usually generalized, chiefly affecting the trunk in a form of numerous erythematous macules & papules that are scaly & arranged along the skin lines (with the ribs) to give a picture of "Christmas tree" distribution. Mild-moderate Pruritus may b present.
Treatment:The disease is benign & self limiting can heal spontaneously without treatment. Oral antihistamines & topical steroids may be used to relief itching. Erythromycin in a dose of 1gm/four times daily for 2weeks can accelerate healing. UVB phototherapy 5 times/week for 2 weeks also found to decrease Pruritus & hasten resolution. In extensive cases with intense itching, systemic steroid can be used in small doses that tapered over 2 weeks.
Prognosis:In most patients, the condition lasts only a matter of weeks; in some cases it can last longer (up to six months). The disease resolves completely without long-term effects but there may be postinflammatory hyperpigmentation especially in black people.
2% of patients may have recurrence.
المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .
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