Actinic keratosis: precancer, squamous cell carcinoma, or marker of field cancerization?

The early detection, recognition, and progression of the actinic keratosis (AK) and its relationship with squamous cell carcinoma have long been an area of debate. Recent advancements in medicine have examined the role of field cancerization in a variety of tumors. The role of AK as a marker for field cancerization will be here discussed.

Identification of bullous pemphigoid, pemphigus, laminin, and anchoring fibril antigens in human fetal skin.

Human fetal skin was evaluated for sequential and regional development of several epidermal antigens. Indirect immunofluorescent methods were used to detect laminin, bullous pemphigoid antigen, pemphigus antigen, and anchoring fibril antigens identified by monoclonal antibodies AF1 and AF2. Eighty-three human fetal skin biopsies from 32 human fetuses were examined. The fetuses examined ranged from estimated gestational age (EGA) of 7-38 weeks. Laminin was present in the basement membrane zone of all the fetal tissues examined. Bullous pemphigoid antigen developed first in the palm and sole, 9 weeks EGA, and was present in all other sites by 17 weeks EGA. Pemphigus antigen was present by 11 weeks EGA. AF1 and AF2 staining was not present until 26 weeks EGA, AF1 and AF2 stained epidermal basal cells in addition to the basement membrane zone area. Comparison of human fetal skin development with basal cell carcinoma identified similarities between basal cell carcinoma and early fetal development.

Immunodermatology update: the immunologically mediated vesiculobullous diseases.

Before a specific diagnosis of an immunologically mediated blistering disease can be made, the clinical and histologic features and the results of direct and indirect immunofluorescence studies (with use of multiple substrates in some cases) must be assessed. For both subepidermal and intraepidermal groups of blistering diseases, direct immunofluorescence testing of perilesional tissue is critical for diagnosis. For these conditions, indirect immunofluorescence testing of serum is important for diagnosis and has a role in management of selected diseases. In dermatitis herpetiformis, indirect testing of serum for IgA antiendomysial antibodies is useful for both diagnosis and management. Indirect testing of serum for IgG antibodies to intercellular substance is important for diagnosis and, in conjunction with the clinical findings, can be used as a guide for monitoring disease activity in patients with pemphigus. Immunoelectron microscopy, immunoprecipitation, and immunoblotting studies have identified the sites of immune deposits and the specific antigens in most of the immunologically mediated bullous diseases. From a practical standpoint, however, direct and indirect immunofluorescence testing, in conjunction with clinical and histologic evaluations, is a simple, rapid, and relatively inexpensive tool for diagnosis and management.

Benign lymphocytic infiltrate of the skin: correlation of clinical and pathologic findings.

In a retrospective study of 137 biopsy specimens of skin from 137 patients (69 men and 68 women) that had been obtained between 1972 and 1989 at our institution and that had perivascular and periappendageal lymphocytic infiltrates characteristic of those described as benign lymphocytic infiltrate (BLI), we determined the specificity of the histologic diagnosis and the correlation with clinical data. The final diagnoses, based on clinical and laboratory data and histologic findings, were BLI (59), possible BLI (7), lupus erythematosus (LE) (12), possible LE (7), procainamide-induced LE (1), insect bites (9), possible insect bites (3), polymorphous light eruption (4), lymphocytoma (4), urticaria (4), and indeterminate or miscellaneous diagnoses (27). BLI is a clinical and histologic syndrome that can be heterogeneous in origin. We recommend careful evaluation to exclude other disorders such as LE, polymorphous light eruption, lymphocytoma, and insect bites. Direct immunofluorescence microscopy and immunophenotypic studies may help distinguish BLI from LE.

Diagnosis of dermatitis herpetiformis by an avidin-biotin-peroxidase method.

BACKGROUND AND DESIGN: Immunofluorescence detection of stippled IgA in dermal papillae has been considered the gold standard in the diagnosis of dermatitis herpetiformis (DH). We have developed an immunohistochemical technique using the avidin-biotin-peroxidase complex that is equally effective as direct immunofluorescence in detecting IgA. We retrospectively studied 43 paraffin-embedded biopsy specimens obtained from patients with DH and a variety of other diseases for the presence of IgA along the basement membrane zone. RESULTS: Eleven immunofluorescence-proved cases of DH were found positive for IgA with the avidin-biotin-peroxidase method. One biopsy specimen originally classified as DH was identified and reclassified as linear IgA bullous disease based on the immunoperoxidase findings. All the samples that were positive on direct immunofluorescence were positive with the avidin-biotin-peroxidase method. Control samples of bullous pemphigoid, discoid lupus erythematosus, pemphigus vulgaris, and dermatitis were all negative for IgA deposition. CONCLUSION: The diagnosis of DH on formalin-fixed tissue is possible with the use of an avidin-biotin-peroxidase method, which is convenient and cost-effective.

Acute hemorrhagic edema of infancy: Finkelstein's disease.

Acute hemorrhagic edema of infancy (AHEI) is a benign form of leukocytoclastic vasculitis limited to the skin, which occurs in children younger than 2 years of age. The abrupt onset of fever, peripheral edema, and purpuric targetoid plaques in an infant may be confused with other dermatoses such as Henoch-Schönlein purpura, Sweet's syndrome, erythema multiforme, or septic vasculitis. Laboratory studies of patients with AHEI typically show normal results and the disorder follows a benign course with spontaneous resolution occurring in 1 to 3 weeks. We present a case of AHEI occurring in a 7-month-old boy and review the characteristic features of this acute dermatosis.

Radiation keratosis associated with exposure to a gold ring.

A radiation keratosis occurred in a woman who wore a radioactive gold ring forty-three years ago. Clinicians should be aware that not all "warty lesions" on the hands are actinic keratosis, seborrheic keratosis, or warts. Radioactive gold rings still exist. Diagnosis requires a high index of suspicion, since patients may no longer be wearing the offending ring.

Bilateral plantar amyloidosis: a unique presentation of localized cutaneous amyloidosis.

Nodular amyloidosis is uncommon and is due to a local production of amyloid by aberrant plasma cells. Localized bosselated plantar amyloidosis has been reported before but we present the first case to our knowledge of bilateral plantar amyloidosis. The clinical presentation as well as therapeutic options for this uncommon entity are reviewed.

Spiny keratoderma.

Spiny keratoderma is a descriptive term used to encompass a variety of unusual, disparate keratodermas. Spiny keratoderma has been associated with lipid abnormalities and has been limited to the palms and soles in some individuals. We describe an acquired case of spiny keratoderma in which an adult woman developed filiform lesions predominating on the trunk and proximal extremities. Treatment with topical emollients and keratolytic agents was unsuccessful, but topical tazarotene led to long periods of resolution. She has had no other associated abnormalities. The clinical features and differential diagnosis of spiny keratoderma are reviewed.

Erythema ab igne caused by a car heater.

Erythema ab igne is a reticulated erythematous hyperpigmented eruption that occurs after chronic exposure to heat. In the past, the shins were the most common area of involvement, but with the widespread availability of central climate control in most buildings the incidence has decreased dramatically. New causes of erythema ab igne have been noted that have been caused by such heat sources as therapeutic chairs with built-in heaters. We present a case in which prolonged and close contact of the legs to a car heater led to erythema ab igne. Practitioners must be aware of the changing causes of erythema ab igne so that an appropriate history can be obtained.

Systemic sarcoidosis presenting in the black dye of a tattoo.

Sarcoidosis is an idiopathic granulomatous disease with many cutaneous manifestations and a known predilection for scars and areas of previous trauma. We report the first case of systemic sarcoidosis presenting in only the black dye of a tattoo. The skin manifestations of sarcoidosis and the histologic differential diagnosis of granulomas are reviewed.

Inexpensive digital photography in clinical dermatology and dermatologic surgery.

Digital photography can be used to follow clinical improvement in a variety of dermatoses, document pre and postoperative results, and document histologic findings from skin biopsies. Images may be printed as part of text documents and can be filed in conventional medical charts. Images can be transmitted via electronic mail rapidly and to any location. We have found digital photography to be relatively inexpensive and a powerful tool to enhance dermatologic practice.

Congenital fascial dystrophy: the stiff skin syndrome.

Congenital fascial dystrophy is an uncommon disorder that may mimic scleroderma. The skin is bound down and feels "wood hard" on palpation of the trunk and extremities. Sclerodactyly, telangiectases, and nail fold changes are not present. Unlike scleroderma, the onset is at birth. Flexion contractures result and other associated abnormalities may include developmental delay and mild hirsutism. We report a typical case to illustrate the clinical and pathologic findings of patients with this disorder.