Τετάρτη 28 Αυγούστου 2013
Τετάρτη 21 Αυγούστου 2013
An Alternative Diagnostic Algorithm for Detecting Pediatric Melanomas
An Alternative Diagnostic Algorithm for Detecting Pediatric Melanomas
Pediatric Melanoma: Results of a Large Cohort Study and Proposal for Modified ABCD Detection Criteria for Children
Cordoro KM, Gupta D, Frieden IJ, McCalmont T, Kashani-Sabet M
J Am Acad Dermatol. 2013;68:913-925
Study Summary
Pediatric melanomas are rare, with patients younger than 20 years of age accounting for 2% of reported melanomas and prepubertal children accounting for only 0.4%.[1] Unfortunately, juvenile melanoma may be misdiagnosed due to a low index of suspicion, absence of conventional ABCDE diagnostic criteria (Asymmetry, Border irregularity, Color variegation, Diameter > 6 mm, Enlarging lesion) and ambiguous histopathology.[2-4] Is there a better diagnostic algorithm for detecting pediatric melanomas?
To address this question, Cordoro and colleagues looked at a cohort of children (< 20 years old) diagnosed with melanoma (N = 60) or ambiguous melanocytic tumors treated as melanoma (N = 10) over a 25-year period of time. These 70 patients were further subdivided into 2 groups: Group A (prepubertal, 0-10 years old, n = 19) and Group B (pubertal, 11-19 years old, n = 51).
Cordoro and colleagues analyzed these pediatric melanoma cases for demographic characteristics, primary lesion characteristics, histopathological characteristics, prevalence of sentinel lymph node and distant metastases, molecular features, melanoma staging, and survival. They made the following main observations:
- Sixty percent of prepubertal melanomas (Group A) and 40% of melanomas presenting near or during puberty (Group B) lacked conventional ABCDE criteria.
- Clinical features associated with pediatric melanomas included: amelanosis, bleeding, "bumps" (nodularity), uniform color, variable diameter, and de novo development.
- The majority of prepubertal melanomas were amelanotic (76%).
- Almost 100% of pediatric melanomas presented with growing ("evolving" or "enlarging") lesions.
- Forty-four percent of these pediatric melanomas could not be histopathologically classified into a current melanoma subtype. Most pediatric melanomas showed nodular, spitzoid, or "unclassifiable" histopathological features.
- Clinically, pediatric melanomas presented at a more advanced stage and behaved more aggressively than melanomas presenting in adults.
- Melanoma risk factors are similar for children and adults (family history of melanoma, dysplastic or numerous melanocytic nevi, immunosuppression, xeroderma pigmentosum).
Viewpoint
This retrospective cohort study confirms that conventional ABCDE criteria will fail to detect pediatric melanomas in a majority of cases, especially in prepubertal children. In contrast, Cordoro and colleagues proposed an alternative set of ABCD criteria for children: Amelanotic bleeding, "Bump," Color uniformity, De novo appearance, any diameter.
In children under 10 years of age, most melanomas were amelanotic and presented as rapidly enlarging nodules, so lesions presenting with these features should be treated as highly suspicious. It should also be noted that most pediatric melanomas, at least in this cohort, presented with nodular, Spitzoid, or unclassifiable histopathology. In this context, dermatopathologists should be aware that melanomas in this age group may be challenging to diagnose and often do not fit conventional melanoma subtypes (superficial spreading, nodular, acral lentiginous).
Σάββατο 17 Αυγούστου 2013
Fresh, Unprocessed Baby Foods Tied to Less Allergy
Fresh, Unprocessed Baby Foods Tied to Less Allergy
By Kerry Grens
NEW YORK (Reuters Health) Aug 09 - Babies who ate more fruits and vegetables and fewer packaged foods were less likely to develop food allergies in a new study that looked at overall diet patterns instead of just specific foods.
"We have been aware that certain diets seem to reduce the risk of allergy in infants," said Dr. Magnus Wickman, a professor at the Karolinska Institute in Stockholm, Sweden, who was not involved in the study.
"The mechanism behind that is that we think that different kinds of fatty acids and antioxidants, different kinds of vitamins and essential minerals are good for your health and also prevent allergy," he said.
Researchers estimate that up to 8% of children have a food allergy.
Parents are sometimes advised to avoid certain foods as a means of preventing food allergies from starting. But Kate Grimshaw, lead author of the new study and a researcher at the University of Southampton in the UK, said she's been concerned that parents are reducing the nutritional diversity of their infants' diet without a great deal of evidence to support the practice.
To see how parents are feeding their infants, and whether that appears to have any influence on food allergies, Grimshaw and her colleagues collected food diaries from the parents of 1,140 babies.
The parents typically maintained the diet log for the first year of life, Grimshaw and her colleagues reported online July 25 in The Journal of Allergy and Clinical Immunology.
During that time, 41 children were diagnosed with a food allergy, and Grimshaw's group compared these infants to 82 similar babies without an allergy.
The researchers scored the babies' diets based on the combination of different foods they ate.
They found that babies without food allergies scored higher than babies with allergies on a diet that was rich in healthy, often homemade, foods - including fruits, vegetables, poultry and fish - and scant on processed foods such as pre-made meals, potato chips, cook-in sauces and bacon.
"The analysis showed that the infants who were having more fruits and vegetables and less commercially produced baby foods and also less adult foods were the ones who were less likely to develop an allergy by the time they were two," Grimshaw said.
"It's not that they didn't have commercially-made baby foods, it's just that they did not have them predominantly in their diet," she added.
The study could not determine why the fresher type of diet seemed to protect against food allergies. And the results do not prove that the dietary patterns caused the differences in allergy rates.
Wickman said that studies on diet and allergy are extremely difficult, and that it is a challenge for researchers to account for other factors that might influence what a child eats and his risk for developing a food allergy.
Still, it's possible that the foods themselves are responsible.
"We know that there are nutrients in the diet that educate the immune system. And one could argue that if they're not there in adequate amounts when the child's immune system is developing, that may be one way that this is working," Grimshaw told Reuters Health.
Wickman said that there is no evidence that avoiding allergenic foods, such as nuts, fish and eggs is beneficial in preventing food allergies.
Also, she said, there is very little risk in recommending that parents focus on fresh fruits and vegetables.
"Healthy food has so many good things, and maybe it also can reduce the risk of food allergy in the child," Wickman told Reuters Health.
Grimshaw said the results are just another reason for parents to feed their children fruits and vegetables and to try to serve home-made meals.
SOURCE: http://bit.ly/17VGTdd
J Allergy Clin Immunol 2013.
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