Chris Commens

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.

Disseminated superficial actinic porokeratosis: A clinical study

Disseminated superficial actinic porokeratosis is an autosomal dominant condition that requires sun exposure for full expression. It affects only sun-exposed areas, with relative sparing of the face. In sun-damaged skin of Australians disseminated superficial actinic porokeratosis is commonly mistaken for solar keratosis. Twenty-nine subjects with disseminated superficial actinic porokeratosis were involved in an extensive questionnaire and clinical study. The distribution of lesions was charted on all subjects, with a mean count of 268 lesions per subject. We found no evidence that skin cancer had arisen in disseminated superficial actinic porokeratosis lesions. A review of the etiologic and clinical features of disseminated superficial actinic porokeratosis also is presented.

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.

CEMENT BURNS: RARE OR RARELY REPORTED?

Prolonged contact with ready mixed cement is a rare cause of severe chemical burns. A 15 year old boy required debridement and skin grafting to a burn on his knee caused by contact with cement. Asa result he lost five weeks from school. We discuss the factors that predispose to this unusual event and pose the question as to why we hear of it so infrequently.

Bindii ( Jo Jo) dermatitis (Soliva pterosperma [Compositae])

Bindii dermatitis is a distinctive eruption occurring in some Australian children during spring and early summer and characterized by discrete erythematous papules with puncta, concentrated over the palms, soles, and knees. In three affected individuals (but not in thirteen controls), pricking the skin with bindii seed produced an erythematous, indurated papule that appeared within 48 hours of intradermal pricking and simulated the primary lesion. Pathogenesis may involve an allergic reaction with a retained depot of antigen rather than a nonspecific foreign body injury reaction.

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.

Hypopigmented malignant melanoma simulating vitiligo

Casereport.An asymptomatic area of hypopigmentation on the posterior right calf developed in a 66-year-old woman 10 years ago.Thisenlarged to 6 ernin diameter andcontained foci of faint mottled erythema. During the2 years just before presentation the centralarea slowly repigmented. The irregularly pigmented centralzonemeasured 2.5emindiameter andclosely resembled the mottled pigmentation of the surrounding sundamaged skin. Skin biopsy specimens were obtained from the area of depigmentation, the central zone of repigrnented skin, and the surrounding sun-damaged skin (Fig. I). All threesites showed anatrophic epidermis and prominent actinic elastosis. Tn thedepigmented area the epidermis showed extensive confluent nests of melanocytes with pleomorphic nuclei and pale cytoplasm (Fig. 2).Pagetoid intraepidermal spread byindividual pleomorphiccells wasevident but dermal invasion was absent (Fig.3). No significant inflammation was present and only minimal fibrosis was shown in the papillary dermis. Rare melanophages were found inthepapillarydermis. Therepigmentedareashowed thesamechanges but also revealed dermal invasion by clusters ofpleomorphic rnelanocytes extending toadepthof0.3 mm(Fig. 4).Schmorls stainformelanin showed a markeddecrease inthe hypopigrnented zonewhereas pigment was readilydemonstrable in biopsy specimens from the surrounding normal skin and the repigmented areabothinmelanocytes andmelanophages inthe papillary dermis. 8-100 and HMB-45 antigens both were demonstrable in the pagetoid cells in the depigmented and repigmented sites. Diagnosis of a superficial spreading melanoma was made and the lesion wasexcised and grafted. Thesurgical specimen showed a malignant melanoma, maximum thickness 0.28 mm, Clark level II. The bulkof the tissue showed an intraepidermal melanoma with isolated small invasive foci that penetrated the papillarydermis. Focal lymphocytic inflammation and papillary fibrosis were present inassociation with extensive actinic elastosis. Prominent horizontal fibrosis was absent. From theSkin and Cancer Foundation. Reprint requests: Dr. Steven Kossard, Skin and Cancer Foundation, 277 Bourke St.,Darlinghurst, 2010,Sydney, N.S.W., Australia. 16/4/15997

MOISTURISER PRESCRIPTION PATTERNS AMONG AUSTRALASIAN DERMATOLOGISTS

One hundred and forty Australasian dermatologists replied to s survey concerning their moisturiser prescribing patterns (67% response rate). Some unexpected local prescription patterns of moisturiser use were detected.

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.