A pilot study on the percutaneous absorption of microfine titanium dioxide from sunscreens

Many Australians are being advised to apply microfine titanium dioxide sunscreen daily from the cradle to the grave. However, there is a surprising lack of data on the percutaneous absorption of microfine titanium dioxide. A prospective pilot study was conducted to analyse the percutaneous absorption of microfine titanium dioxide from sunscreens. Selected patients scheduled to have skin surgery, applied titanium dioxide sunscreen to the skin daily for 2–6 weeks prior to their operation. After excision, the stratum corneum of the sample was stripped and the titanium concentration of the remaining epidermis and dermis was measured by inductively coupled plasma-mass spectrometry. The results from this pilot study showed that levels of titanium in the epidermis and dermis of subjects who applied microfine titanium dioxide to their skin were higher than the levels of titanium found in controls. Studies with larger cohorts are necessary to establish if this absorption is statistically significant.     

SQUAMOUS CELL CARCINOMA IN POROKERATOSIS IN TWO PATIENTS

Malignancy arising in porokeratoses is a well recognised but infrequently reported complication. Histological studies suggest that malignancy arises from the abnormal clone of keratinocytes which produce the cornoid lamella. We report two cases of squamous cell carcinoma arising in porokeratoses and postulate genetic, environmental and host factors as important in the evolution of their malignancy.     

BENIGN CEPHALIC HISTIOCYTOSIS

A 3 year old boy had an asymptomatic pigmented maculopapular eruption on his face for 2½ years. This rash partially resolved in summer and remitted in winter. Skin biopsy and ultrastructural studies showed a histiocytic infiltrate with “comma shaped” cytoplasmic inclusions, confirming the diagnosis of Benign Cephalic Histiocytosis. We review the features of this condition and compare it with other self healing histiocytotic conditions.     

LENTINGINOUS DYSPLASTIC NAEVI IN THE ELDERLY: A POTENTIAL PRECURSOR FOR MALIGNANT MELANOMA

Seventy-seven skin biopsies diagnosed histologically as lentiginous junctional naevi from individuals aged over 60 years were reviewed. Seventy-three specimens showed a primarily nested pattern with disordered arthitecture concentrated within the rete ridges conforming to the pathology of a lentiginous dysplastic naevus. In 28 biopsies this was combined with a melanoma in situ. The latter was reflected by a focal loss of the rete ridge system, confluent melanocytic hyperplasia and single cell invasion of the epidermis by atypical malanocytes. Four biopsies showed lentiginous junctional naevi with only isolated naevus cell nests without a disordered architecture or cellular atypia. Thirty-seven of the 57 naevi in men were located on the back in contrast to 5 of the 20 women. In women the lower limb was the most frequent site with 8 of the 20 lesions originating at this site in contrast to 1 of the 57 men. The pathological diagnosis of dysplastic lentiginous naevi in the elderly needs to be recognised as having a high association of melanoma-in-situ changes.     

Survey of phototherapy practice by dermatologists in Australia

A postal survey was sent to all dermatologists in Australia to determine current phototherapy practices. Questionnaires were returned by 158 (57%) of 277 dermatologists, of whom 112 (71%) provided phototherapy. Large variations existed in attitudes and practice, including indications, contraindications, dosage schedules, equipment maintenance, response to adverse events, and follow-up arrangements. Cumulative ultraviolet (UV) doses for psoralen and UVA (PUVA) were not calculated by 21%, while 30% did not calculate cumulative doses for UVB. Written informed consent was not obtained by 32%. Phototherapist dermatologists reported 25 patients developing melanoma following PUVA. Only 30% of Australian dermatologists organize regular follow up of patients after phototherapy. Australians have the highest rates of melanoma and non-melanoma skin cancers in the world, because of their ancestry and high solar exposure. This makes it inappropriate for Australian dermatologists to rely entirely on foreign safety data when assessing the risks and benefits of phototherapy in Australian patients. There is a need for standardized Australian guidelines that can be prospectively assessed to ensure phototherapy is used to maximize efficacy and minimize risks in Australian patients, given their unique ancestral mix and outdoor lifestyle.     

The use of gloves in Australian dermatological practice

Dermatologists use gloves as a major tool in universal precautions to prevent transmission of infections particularly human immunodeficiency virus (HIV) and hepatitis. We need to know how much protection is conferred by gloves and what problems are associated with glove use. This paper looks at these issues and reports the results of a survey on glove use by Australian dermatologists. The survey found a lack of awareness regarding gloves as a protective measure, suggesting the need to improve knowledge in this area so that realistic precautions can be adopted. Dermatologists have a high rate of glove use and reactions to gloves were noted by 13% of respondents. The authors recommend the use of non-powdered, low-allergen latex gloves. Handwashing prior to using non-powdered latex gloves needs further investigation. Handwashing after wearing latex gloves may decrease sensitization risk.     

Disseminated superficial actinic porokeratosis. A histological review of 61 cases with particular reference to lymphocytic inflammation

The pathology of 61 cases of disseminated superficial actinic porokeratosis was reviewed and the relative frequency of the histological features associated with the cornoid lamella and the pathology within and outside the porokeratotic rim were assessed. Papillary dermal lymphocytic infiltrate (97%), spinous layer vacuolar changes (90%), dyskeratotic cells in the epidermis (77%), and liquefaction degeneration of the basal layer (67%) were frequently seen under the cornoid lamella. Papillary lymphocytic infiltration was seen more frequently inside the porokeratotic ring in comparison to the outer skin. Lymphocyte marker studies in nine cases showed a predominance of activated T lymphocytes with positive LN3 and UCHL-1 staining. Together with the finding of a lichenoid reaction pattern, these results lend support to the hypothesis that actinic porokeratosis represents a migrating clone of abnormal keratinocytes with an associated immunological host response.     

Scrubbing for cutaneous procedures can be hazardous

Office-based minor cutaneous surgery is a service provided by many medical practitioners. In New South Wales, Australia, it is a legal requirement for practitioners to surgically scrub before donning sterile gloves for all forms of invasive surgery, including minor cutaneous procedures. Frequent scrubbing causes altered skin barrier function, irritant dermatitis and a potential risk of latex sensitization. These adverse effects are associated with significant morbidity and cost. Better tolerated alternatives, including alcohol-based hand rubs, should be considered in preference to traditional surgical scrubs in order to reduce these occupational risks for minor proceduralists. Well-controlled, prospective studies should explore what extent of hand washing is necessary for donning sterile gloves for minor cutaneous surgery.