Psoriasis

Diagnosis and Management

Wolfram Sterry, Robert Sabat, Sandra Philipp, Wolfram Sterry, Robert Sabat, Sandra Philipp

• Publisher: Wiley-Blackwell
• Year: 2014
• ISBN:
  9781118661819
• Edition: 1
• Topic: Medicine
• Subtopic: Dermatology

Practical and user-friendly, this is the ideal guide to the diagnosis and treatment of psoriasis, helping you navigate a logical management pathway through a complex maze of possibilities. Psoriasis is a cruel disease that can seriously affect the sufferer's quality and length of life. It is also highly idiosyncratic, with features that vary greatly from patient to patient; this being mirrored in the highly variable response to treatment. It is increasingly recognized that psoriasis is not a discrete disease and that many patients suffer two or three comorbid conditions that can complicate the efforts of doctors treating patients. Psoriasis: Diagnosis and Management will provide dermatologists of all levels with a practical, well-illustrated approach to fully understanding the disease, including clear, clinical guidance to enable best-practice and effective management of patients. In full color throughout and excellently illustrated, key highlights include:

• easily understandable description of the psoriasis pathogenesis;
• a strong emphasis on the clinical features of psoriasis;
• careful consideration of comorbid conditions as part of the psoriatic spectrum to be managed;
• coverage of both traditional and contemporary management approaches;
• plenty of diagnostic algorithms and management protocols to aid the daily practical care of patients.

Brought to you by several of the world's leading authorities on the subject, Psoriasis: Diagnosis and Management is an essential purchase for the dermatologist.

Part I
Epidemiology and economic aspects

Chapter 1
Epidemiology and economic aspects

Luigi Naldi, Simone Cazzaniga, and Giovanna Rao

Bergamo General Hospital, Bergamo, Italy

Epidemiology

Epidemiologic research should be understood in the light of its main interest, that is, prevention of the disease and its consequences in man.

Descriptive epidemiology

The measures employed are incidence and prevalence. A first step in descriptive epidemiology is to obtain a valid definition of what constitutes a “case.” Quite surprisingly, up to now, no widely employed diagnostic criteria have been developed for clinical and population based studies of psoriasis. The first diagnosis made by a physician and the first appearance of skin lesions as reported by the patient have both been taken as markers of “onset” in epidemiologic studies.

Incidence—there are few studies

In a pilot study conducted in Rochester, Minnesota, in the period 1980–1983, incident cases were defined as patients requiring, for the first time in their life, medical care for a condition diagnosed as psoriasis. The age- and sex-adjusted (1980 US white population) annual incidence rate was 60.4 per 100,000 people. The crude rates were 54.4 for men and 60.2 for women. In another study from the United States, a cohort of 1633 adult subjects was followed up from 1970 to 2000. Rates adjusted to the 2000 US population increased significantly over time from 50.8 in the period 1970–1974, to 100.5 per 100,000 in the period 1995–1999. In a third study from the United States, a cohort of people younger than 18 years was followed up between 1970 and 1999. The overall incidence of psoriasis age- and sex-adjusted to the 2000 US population was 40.8 per 100,000. The incidence increased steadily with increasing age. Moreover, incidence increased in most recent years in both boys and girls. In a study based on data from the United Kingdom General Practice Research Database (UKGPRD) where cases were recorded by general practitioners from January 1996 to December 1997, a rate as high as 14 per 10,000 person-years was estimated, much higher than rates in the United States.

Prevalence

Each new case (incident case) enters the prevalence pool and remains there until either recovery or death. If recovery and death are not frequent, even low incidence rates (such as those calculated for psoriasis) produce a high prevalence. Prevalence measures may be relative to a point in time (point prevalence) or to a longer period (period and lifetime prevalence). Prevalence of psoriasis “ever experienced” in the past at any age (i.e. lifetime prevalence) approximates the cumulative incidence in that age group, that is, the proportion of the birth cohort developing the disease until the time of survey, provided that psoriasis does not affect mortality per se and that the recall of past episodes is complete.

Results of selected studies of the prevalence of psoriasis in defined populations provide estimates ranging from 0.05% in China to 4.8% in Norway (Table 1.1). Besides geographic variations, these estimates are expected to change according to the period considered, that is, point prevalence vs “lifetime prevalence.” In addition, variations may be expected to arise from differences in case definition and ascertainment, and from differences in age distribution of dynamic populations.

Table 1.1 Selected estimates of the prevalence of psoriasis.

Country	Ascertainment method	No. of subjects (age)	Measure^a	Estimate ×100
Faroe Islands	Clinical examination	10,984	PT	2.8
Norway	Questionnaire	14,667 (20–54 years)	LT	4.8
Norway	Questionnaire	10,576	PT	1.4
Sweden	Monitoring of diagnoses	159,200	PP	2.3
Denmark	Questionnnaire	3892 (16–99 years)	LT	4.2
Croatia	Clinical examination	8416	PT	1.5
USA	Clinical examination	20,749 (1–74 years)	PT	0.8–1.4^b
China	Monitoring of diagnoses	670,000	PT	0.05–0.84
England	Questionnaire and clinical examination	2180	PT	0.6–1.6^b
Australia	Questionnaire and clinical examination	1037 (adults)	PT	2.3
Italy	Questionnaire	3660 (>44 years)	LT	3.1
Germany, working adults	Examination	90,880	PP	2.0
USA	Questionnaire	10,122	LT	3.1
Sweden, male conscripts	Examination	1,226,193 (20 years)	LT	0.5
United Kingdom UKGPRD	Examination	7,533,475	PP	1.5
USA (Caucasians vs African Americans)	Questionnaire	21,921 vs 2443	LP	2.5 vs 1.3
Spain	Questionnaire	12,938	LP	1.17–1.43
Portugal	Questionnaire and clinical examination	1000	PP	1.9

^a LT: lifetime prevalence; PP: period prevalence; PT: point prevalence.

^b Different estimates are provided according to severity indexes, or age groups.

Ethnic and geographic variations

It appears that Mongoloid races in the Far East of Asia have remarkably low prevalence rates. Lower...

Table of contents

• Cover
• Title page
• Copyright page
• List of contributors
• Preface
• Part I: Epidemiology and economic aspects
• Part II: Etiology and pathogenesis
• Part III: Clinical features/diagnostic procedure
• Part IV: Evaluation of disease severity
• Part V: Psoriasis and associated diseases
• Part VI: Therapeutic management
• Index
• End User License Agreement