Indicated Supporting Diagnostic Data

Case history is critical to the discovery of a specific cause in acute, intermittent, or chronic urticaria. Testing should be guided by historical data, and extensive blind testing is seldom productive. History should be repeated periodically, as the victim may recall forgotten information or, over time, may make new associations. Biopsy is seldom indicated for urticaria when a question arises regarding common hives versus urticarial vasculitis (see Differential Diagnosis section), biopsy will...

Clinical Application Questions

A 48-year-old woman is seen for intensely pruritic raised lesions on her trunk and extremities of 3 weeks' duration. Clinically her lesions look to you like hives. 1. What questions should you ask the patient about the lesions to support your suspicion 2. Would this most likely be classified as acute urticaria, chronic urticaria, or chronic intermittent urticaria, and why 3. Assuming this is acute urticaria, what history should be sought to establish a possible cause 4. Assuming this is acute...

Conditions That May Simulate Acne Vulgaris

Papulopustular rosacea may resemble acne, but usually occurs on a backdrop of flushing and telangectasia. Comedones and cysts are absent except in rare cases when both diseases occur simultaneously. Most rosacea lesions are on the face. This localized eruption is almost exclusively limited to female patients. It presents with a localized papular and eczematous eruption with tiny pinpoint pustules in the perioral, perinasal, or periocular areas of the face. It superficially resembles acne, but...

Specific History

Initial symptoms of tinea infections vary based on the host, site, and organism. Tinea capitis Tinea of the scalp (TCa) is most common in preschool children and pre-teens and is uncommon in adults. It should be part of the differential of any scalp condition that presents with patchy hair loss, inflammation, scaling, a localized inflammatory lesion, or follicular pustules. In children, the onset is usually abrupt and parents usually recount symptoms of redness, scaling, or hair loss of only a...

Conditions That May Simulate Herpes Simplex Recidivans

Both diseases are common in the central facial region, and both begin with small clear vesicles on an inflammatory base. Herpetic lesions tend to remain fixed and discrete, and the vesicles are small, 1 to 2 mm across, tightly grouped, and persist for longer periods. Facial HSV occasionally develops secondary impetigo, causing some diagnostic confusion. A smear with a Gram stain will often show bacteria with cases of impetigo. A Tzanck smear of a blister base will show herpes virus cytopathic...

Conditions That May Simulate Psoriasis Vulgaris

SD of the scalp, face, and ears may be clinically and microscopically indistinguishable from PV. Biopsy is often of no value because at this point both diseases can show similar findings. Family history and follow-up will usually separate the two. The lesions of PV develop a deeper color, are more raised, and develop a silvery rather than yellow scale. In addition, PV lesions tend to be more fixed and circumscribed than SD lesions. In the absence of other lesions, the presence of linear nail...

Dermatologic Physical Exam

Primary LP lesions are red to deep violet, flat-topped, angular geometric (polygonal) 1- to 3-mm papules. The papules may be separate or tightly grouped (see Photo 31). Wickham's stria are a lacy network of white lines seen on the surface of the papules considered pathognomonic for LP (see Photo 32). Early lesions tend to be red to dusky deep red. As the papules mature they acquire a deep violaceous hue, which is considered typical. As pigment is dropped from the basal cell layer some lesions...

Conditions That May Simulate Atopic Dermatitis

This eruption is partially eczematous and partially papulosquamous. Onset and distribution are similar to those for infantile atopic dermatitis. Differentiation is particularly difficult when the eczema component is predominant. Both conditions may exhibit heavy scale. While the scale of seborrhea is yellow and greasy, that of atopy is white and dry. The distinction is not always easy to make. Seborrhea lesions tend to have sharp margins, while those of atopic dermatitis are indistinct. In...

Therapy

Dermatologic treatment usually involves the use of topical therapy, which is a discipline unto itself. This form of treatment was primarily an art until about 20 years ago. Since then science has begun to unravel the biology of the epidermis, making it a more scientific process. Much of topical therapy is simply not written down and it is more complicated than the old bromide, If it's wet, dry it if it's dry, wet it. This discussion will cover some basic principles of topical therapy, but is by...

Conditions That May Simulate Tinea

Tinea of the scalp may be confused with any scalp disorder that causes patchy alopecia, inflammation, or scale. The presence of hairs broken off a short distance above or right at the scalp surface should cause immediate suspicion. Occasionally TCa does not produce hair breakage. The noninfectious dermatidities seborrhea and psoriasis can both cause inflammation and scaling of the scalp, but do not cause patchy hair shedding. Both are more diffuse than TCa. When any inflammatory scalp condition...

Macrodistribution

Psoriasis Points

Classic Scalp, pressure points over extensor surface of joints, presacral and upper gluteal clefts, glans penis. Psoriasis may occur on any skin surface see Fig. 8 . Figure 8 Macrodistribution of psoriasis vulgaris. Figure 8 Macrodistribution of psoriasis vulgaris. 2. Inverse Creases and folds. An uncommon intertriginous form is referred to as inverse psoriasis. 3. Generalized erythrodermic Generalized red skin. Lesions tend to be symmetric from side to side and across the midline, even in...

Molluscum Contagiosum Dimple Warts

Warts Pubic Area

A 16-year-old male high school student presents with a large number of papular lesions of recent onset in the right thoracic and axillary region. There is a second grouping of similar lesions on the right knee. The patient is on the wrestling team, desires removal of the lesions, and was sent to you by his wrestling coach to find out if they might be contagious. You suspect this is molluscum contagiosum. 1. What are the primary lesions you would expect to find in molluscum contagiosum 2. What...

Dermatologic Physical Examination

Dermal Atrophy Dermatopathology

The four components of the dermatologic physical examination are 1 primary lesions, 2 secondary lesions, 3 distribution, and 4 configuration. Because primary and secondary lesions are rather constant with most dermatitides, they should be relied on heavily to lead to the correct diagnosis. The two other basic components of the physical exam, distribution and configuration, are used for support and confirmation. Some skin disorders lack a distinct distribution or configuration. Occasionally,...