Reticulate pigmentary disorders.

Reticulate pigmentary disorders is a term that is loosely defined to include a spectrum of acquired and congenital conditions with different morphologies. The presentations vary from the reticular or net like pattern to the" freckle like" hyper and hypopigmented macules that are usually restricted to the true genetic "reticulate" pigmentary disorders. There is little clarity on this topic and related terms, in major dermatology textbooks. Hence, to harmonize the different entities we feel that the term "mottled pigmentation" could be used to include reticulate pigmentary disorders (acquired and congenital), dyschromasias and the disorders with a reticular pattern. The genetic reticulate pigmentary disorders can also be classified according to the gene loci which in the majority of cases are localized to keratin 5/14. A more useful clinical method of classification is based on the regional distribution, which includes facial, truncal, acral or flexural types. In this review we will largely focus on the inherited reticulate pigmentary disorders.

An open, nonrandomized, comparative study of imiquimod 5% cream versus 10% potassium hydroxide solution in the treatment of molluscum contagiosum.

BACKGROUND: There are numerous therapeutic modalities available for treatment of molluscum contagiosum. However, the ablative modalities are painful and not suitable for children. AIM: We aimed to evaluate and compare the safety and efficacy of 2 of the painless modalities, viz., 5% imiquimod cream and 10% potassium hydroxide (KOH) solution, in the treatment of molluscum contagiosum. METHODS: Out of a total of 40 patients of molluscum contagiosum in the study, 18 patients in the imiquimod group and 19 patients in the KOH group completed the study. The given medication was applied by the patient or a parent to mollusca at night, 3 days per week. Imiquimod was continued till clinical cure; and 10% KOH, till lesions showed signs of inflammation. Assessments of response and side effects were performed at the end of week 4, week 8, and week 12. Significance was tested by Student's t test and Mann-Whitney test. RESULTS: The mean lesion count decreased from 22.39 to 10.75 with imiquimod and from 20.79 to 4.31 with KOH at the end of 12 weeks. We found complete clearance of lesions in 8 (44%) patients with imiquimod and in 8 (42.1%) patients with 10% KOH. Minor side effects were seen in 15 (78.9%) patients on KOH and 10 (55.5%) patients on imiquimod. CONCLUSIONS: The results of this study suggest that both 5% imiquimod cream and 10% KOH solution are equally effective in molluscum contagiosum though KOH has a faster onset of action. However, KOH solution is associated with a higher incidence of side effects.

Condom leukoderma.

Contact dermatitis from natural latex of condom has been reported and is attributed to latex sensitivity. Chemical leukoderma from rubber condom is probably not reported. Here we present a case of chemical leukoderma in a 32-year-old male who developed depigmentation around the shaft of the penis in a circumferential pattern. Since the lesion was solitary and the site corresponded to the point of maximum contact of the condom, a diagnosis of contact leukoderma due to latex condom was thought of. Patch testing was done with mercaptobenzothiazole (MBT), dusting powder present in the condom and condom latex as such. The patient tested positive (3+) with mercaptobenzothiazole and the condom latex. On discontinuation of condom use and with UVB phototherapy, lesions repigmented in eight weeks.

Hyperpigmented dermal macules in children following the administration of Maloprim for malaria chemoprophylaxis.

The occurrence of an unexpected side effect following the use of Maloprim (pyrimethamine/dapsone) for malaria chemosuppression in 3-59 months old children in Sierra Leone is reported. As part of a trial of chemoprophylaxis and insecticide-impregnated bed nets, 2000 children received either Maloprim or placebo; 4% of children who received Maloprim fortnightly for more than 3 months developed hyperpigmented macules, whereas none of the children who received placebo did so. Histopathological examination of full thickness skin biopsies showed macrophages containing melanin in the dermal layer. Clustering of cases was noted among siblings, suggesting the possible involvement of genetic factors in the pathogenesis of these skin reactions. One child was accidentally re-exposed to Maloprim after the drug had been withdrawn and he developed a severe reaction. No other serious side effect was noted. Hyperpigmented lesions similar to those reported in this study have been described previously in patients with leprosy treated with dapsone, and the dapsone component of Maloprim is the likely cause of the skin reactions seen in children given this drug for malaria chemoprophylaxis.

Treatment of localized Mycobacterium avium complex infection with clofazimine and doxycycline in a cat.

Mycobacterium avium complex infection resulted in a granuloma that developed at the base of the left ear in a cat. The lesion caused vestibular dysfunction and facial palsy on the left side and protruded into the oral cavity on that side. The cat was treated successfully, with resolution of the lesion and elimination of the organism, by use of combined administration of clofazimine and doxycycline. Adverse effects of the clofazimine treatment included temporary reddish-orange discoloration of the cat's skin and mucous membranes.

Skin pigmentation from clofazimine therapy in leprosy patients: a reappraisal.

Skin biopsy specimens from two lepromatous leprosy patients with dark brown pigmentation who were receiving long-term clofazimine therapy were studied. Ceroid-lipofuscin pigment was demonstrated inside macrophages that contained numerous phagolysosomes. These contained lipids and clofazimine that appeared as electron-lucent vacuoles and a lipofuscin pigment that was electron dense, granular, and lamellated. Although the presence of the drug in tissues contributed to the skin pigmentation, the main cause was a drug-induced, reversible ceroid lipofuscinosis.

A study of dermatological conditions in leprosy in-patients.

Three hundred and sixty six in-patients in a leprosy hospital were examined for other dermatological conditions. Eighty eight of them displayed ichthyosiform changes. A peculiar condition of a verrucous hyperkeratotic growth on the anterior aspect of ankle, not described previously, was observed in four patients. It was noted that 11 out of 12 patients with scabies did not have the classical lesions in web spaces of the hands.

Intra-neural ceroid-like pigment following the treatment of lepromatous leprosy with clofazimine (B663; Lamprene).

A 33 year old male Nigerian presented with widespread involvement of peripheral nerves, several of which were tender and painful. Nerve biopsies confirmed the presence of Mycobacterium leprae in both endoneurial and perineurial areas, mainly in foamy macrophages (Virchow cells), but there were also large accumulations of an amorphous, acid-fast and alcohol-fast material which was not obviously of bacterial origin. Appropriate stains indicated that this had many characteristics of lipofuscin. Although not previously known, it was at this stage discovered that the patient had received treatment with anti-leprosy drugs nearly three years before presentation in this country. One of these was clofazimine, an aniline aposafranine derivative known to produce a ceroid-like pigment in the tissues of patients treated with this drug or lepromatous leprosy.

Histochemistry of B663 pigmentation: ceroid-like pigmentation in macrophages.

Histochemical studies were made of pigmented cutaneous lesions from three cases of lepromatous leprosy treated with B663 to determine the nature and histogenesis of the brown pigmentation which develops as a side effect of the drug. One case of DDS-treated leprosy and four cases of untreated leprosy were also investigated histochemically as controls. The brown pigmentation of the skin is due to deposition of a ceroid-like substance in the macrophages, which is a yellowish-brown, acid-fast lipid pigment. It is insoluble in fat solvents and accepts lipid dyes even after lipid extraction by fat solvents. The macrophages in the B663-treated leprosy contain more neutral fat and less phospholipid than the untreated lepromatous leprosy tissues. Ceroid in the macrophages probably originated from unsaturated fatty acids of the leprosy bacilli through oxidation or their binding with the drug. Crystals of the drug were not found in the macrophages in this series, even on the tissues embedded in carbowax or frozen sections.