Total body skin examination increases squamous cell carcinoma detection: a retrospective cohort study.

Squamous cell carcinomas (SCCs) have the potential for local tissue destruction and metastasis. The risk of complications increases if the lesion is not diagnosed and excised in a timely manner. Total body skin examination (TBSE) has been reported to increase melanoma detection; the objective of this study was to determine if it also increases SCC detection. Analysis of 469 SCCs diagnosed at a UK tertiary centre showed that 6.8% of these were detected incidentally and not from the index lesion that prompted referral. These incidentally detected SCCs tended to represent early disease, and therefore carried lower risk of complications. Our findings suggest that full skin checks may increase the number of SCCs detected, and at an earlier stage of disease. Therefore, we encourage the use of TBSE in all dermatology outpatient appointments, and make suggestions as to how to incorporate it into the limited time available in dermatology clinics.

Generalized granuloma annulare in a photosensitive distribution resolving with scarring and milia formation.

We describe an unusual case of generalized granuloma annulare (GA) in a 70-year-old man. This occurred in a photosensitive distribution, responded rapidly to topical and systemic treatment, and resolved leaving residual scarring and milia. To our knowledge, this is the first report of the occurrence of milia formation and scarring in association with GA.

Mate choice turns cognitive.

Evolutionary psychology has revolutionized research on human mate choice and sexual attraction in recent years, combining a rigorous Darwinian framework based on sexual selection theory with a loosely cognitivist orientation to task analysis and mechanism modelling. This hard Darwinian, soft computational approach has been most successful at revealing the adaptive logic behind physical beauty, demonstrating that many sexual cues computed from face and body shape are not arbitrary, but function as reliable indicators of phenotypic and genetic quality. The same approach could be extended from physical to psychological cues if evolutionary psychology built stronger ties with personality psychology, psychometrics and behavioral genetics. A major challenge for mate choice research is to develop more explicit computational models at three levels, specifying: (1) the perceptual adaptations that register sexual cues given sensory input, (2) the judgment adaptations that integrate multiple cues into assessments of overall attractiveness, and (3) the search strategies that people follow in trying to form mutually attracted pairs. We describe both recent efforts and possible extensions in these directions. The resulting confluence between evolutionary principles, cognitive models and game-theoretic insights can put mate choice research at the vanguard of an emerging `evolutionary cognitive science' more concerned with domain-specific mental adaptations than with domain-general intelligence.

Explaining social learning of food preferences without aversions: an evolutionary simulation model of Norway rats.

Norway rats (Rattus norvegicus) transmit preferences for novel foods socially by smelling each other's breath. However, rats fail to learn aversions, acquiring a preference even if the rat whose breath they smell has been poisoned. Rats can distinguish between sick and healthy conspecifics and social learning of both preferences and aversions is present in other species - hence it is unclear why rats cannot learn aversions socially. We constructed an evolutionary simulation in which a population of rats foraged from a central location, exploiting food sites that could contain edible or toxic foodstuffs. We examined the relationship between toxin lethality and selection for individual versus social learning and discrimination between sick and healthy conspecifics in order to allow learning of both preferences and aversions. At low lethality levels individual learning was selected for and at intermediate levels we found social learning of both preferences and aversions. Finally, given high lethality levels the simulated rats would employ social learning but failed to learn aversions, matching the behaviour of real rats. We argue that Norway rats do not learn aversions socially because their environment may contain only highly lethal toxins which make interaction with a sick conspecific an extremely rare event.

Précis of Simple heuristics that make us smart.

How can anyone be rational in a world where knowledge is limited, time is pressing, and deep thought is often an unattainable luxury? Traditional models of unbounded rationality and optimization in cognitive science, economics, and animal behavior have tended to view decision-makers as possessing supernatural powers of reason, limitless knowledge, and endless time. But understanding decisions in the real world requires a more psychologically plausible notion of bounded rationality. In Simple heuristics that make us smart (Gigerenzer et al. 1999), we explore fast and frugal heuristics--simple rules in the mind's adaptive toolbox for making decisions with realistic mental resources. These heuristics can enable both living organisms and artificial systems to make smart choices quickly and with a minimum of information by exploiting the way that information is structured in particular environments. In this précis, we show how simple building blocks that control information search, stop search, and make decisions can be put together to form classes of heuristics, including: ignorance-based and one-reason decision making for choice, elimination models for categorization, and satisficing heuristics for sequential search. These simple heuristics perform comparably to more complex algorithms, particularly when generalizing to new data--that is, simplicity leads to robustness. We present evidence regarding when people use simple heuristics and describe the challenges to be addressed by this research program.

Hidradenitis suppurativa, Dowling-Degos and multiple epidermal cysts: a new follicular occlusion triad.

This case illustrates the rare association between hidradenitis suppurativa (HS) and Dowling-Degos disease (DDD). Furthermore the association of HS, DDD and multiple epidermal cysts has not to our knowledge been described before, but their coexistence in the same patient is likely to reflect the same follicular anomaly. It is possible that a single underlying defect of follicular proliferation may account for the coexistence of these conditions.

Antiepiligrin (laminin 5) cicatricial pemphigoid complicated and exacerbated by herpes simplex virus type 2 infection.

A 50-year-old man with antiepiligrin (laminin 5) cicatricial pemphigoid (AeCP) involving the eyes, mouth and skin required a combination of systemic drug therapies to suppress the ocular disease. Herpes simplex virus type 2 infection of the mouth and pharynx precipitated an acute deterioration, with laryngeal involvement and an increase in oral ulceration. This is an unusual complication of long-term immunosuppression and illustrates some of the difficulties in the management of patients with AeCP. Clinical improvement was obtained with oral antiviral therapy and adjustment of his immunosuppressive regimen.

An immunohistological study of cutaneous lymphocytes in vitiligo.

In a study of 49 biopsies from the margins of depigmented cutaneous lesions in 18 patients with vitiligo, highly significant overall increases were found in CD3+, CD4+, and CD8+ T cells, though cell numbers in individual cases were often within the normal range. Many of the T cells were activated (MHC class II+, interferon gamma+), of CD45RO (UCHL1+) memory subset, and many expressed the cutaneous lymphocyte-associated antigen (HECA-452+) typical of skin-homing T cells. Immunohistologically, the most intense epidermal T-cell infiltration was present within 0.6 mm of the edge of the lesion in 10 of 13 double-stained sections with a clearly defined zone of melanocyte depletion. In 40 lesions from 17 patients seen 11-64 weeks after biopsy, no apparent association was found between T-cell numbers and disease activity as assessed by Köbnerization of biopsy wounds or spread of depigmentation. These findings are consistent with the hypothesis that lesional T cells rather than circulating antimelanocytic antibody may be responsible for the supposedly autoimmune but characteristically patchy destruction of cutaneous melanocytes in vitiligo. Nevertheless, many of the infiltrating T cells are probably innocent bystanders attracted by upregulated cell adhesion molecules near sites of melanocyte damage.

Abnormal expression of MHC class II and ICAM-1 by melanocytes in vitiligo.

The relationship between damage to cutaneous melanocytes and antimelanocyte autoimmunity in vitiligo is unclear. We have demonstrated abnormal expression of MHC class II molecules by perilesional melanocytes in 13/21 patients with vitiligo and a six-fold increase in the number expressing the intercellular adhesion molecule ICAM-1. These molecules have important roles in normal antigen presentation and activation of helper T lymphocytes, and their expression by melanocytes may contribute to the abnormal immune response in vitiligo. MHC class II is not expressed by melanocytes in psoriasis and is unlikely to be induced in vitiligo by cytokines released from activated non-melanocyte-specific T lymphocytes.