Papulosquamous lesions

Overview
Papular skin lesions that occur on the squamous layer of the skin. These lesions are classified as exanthems have obvious changes with scale. Within the papulosquamous categories, diagnoses tend to be relativly broad and should be considered after history and physical exam are taken. Lesion distribution is helpful in determining a diagnosis.

Differential Diagnosis
In alphabetical order.


 * Allergic reactions (included in papulosquamous diseases)
 * Atopic dermatitis
 * Eczematous disease
 * Fungal infections of the skin (may be caused by dermatophytes)
 * Infections
 * Lichen planus
 * Nummular eczema
 * Pityriasis rosea
 * Psoriasis
 * Seborrheic dermatitis

History and Symptoms

 * Family history
 * Seborrhea of the face is very common
 * Pityriasis rosea - Occurs in young adults subsequent to a viral prodome, thicker herald patch should help to determine diagnosis
 * Atopic dermatitis - consider in young patients with allergic rhinitis / asthma, very itchy and uncomfortable subacute rash

Extremities

 * fingernail pitting
 * subungual debris
 * distal seperation of the nail plate form the nail bed

Laboratory Findings

 * Labs include:
 * Patch testing for allergies and chemical exposure

Other Diagnostic Studies

 * KOH prep by light microscope can determine dematophyte infection

Acute Pharmacotherapies

 * Psoriasis - Topical steroids, tar, anthralin preps, intralesional steroids, salicylic acid, UV therapy, methotrexate, acitretin, cyclosporin
 * Pityriasis rosesa - oral antihistamines, topical steroids, topical antipruritics
 * Atopic dermatitis - repair skin with gentle emollients, cleansers and topical steroid ointments

Chronic Pharmacotherapies

 * Psoriasis - Topical calcipotrine