Acrodermatitis Continua of Hallopeau

Acrodermatitis continua can be resistant to treatment. It may be treated topically with glucocorticoids, calcipotriol, 5-fluorouracil or tacrolimus. Systemic treatments include oral retinoids, cyclosporine, methotrexate, and PUVA photochemotherapy. There are reports of improvement with NSAIDs. A combination of tacrolimus in the morning and calcipotriol at night is probably the best approach often showing very good improvement in 3 weeks. A previous patient of mine reported very good improvement with alternative medicine!

 

Emollients and Phototherapy in Psoriasis

Traditionally patients are advised not to apply emollients prior to phototherapy as emollients can have a sunscreen effect leading to sub optimal response to phototherapy. Is this always true?

A very close look at the optical properties of skin shows that emollients can actually be a double edged sword.

As light passes from one medium to another of different refractive indices, part of it gets reflected. The amount of light reflected depends on the difference of refractive index between the media.

In psoriasis the air between the scales creates multiple refractive surfaces leading to loss of UV during phototherapy. Hence if we can use an emollient with a refractive index similar to skin it can actually increase the penetration of UV.

This is not just a theoretical concept. Studies have shown that there are emollients with Monochromatic Protection Factor (MPF) in the 313-315 range (Narrow Band UVB) of less than 1, which means that penetration is more than uncovered skin!

Hence emollient manufacturers should think about introducing products tailor made for psoriasis patients on phototherapy.

If anybody want to explore this concept further or need help with MPD determination do contact me.

 

Idiopathic Guttate Hypomelanosis

Idiopathic guttate hypomelanosis is traditionally a disease of the fairer skin. It is one of the few photoinduced hypopigmented lesions. Today I say one patient with multiple IGH. Some dermatologists use topical psoralen preparations though theoretically it can worsen IGH. The treatments of choice include topical steroids, tretinoin and sunscreens.

 

What is your diagnosis?

 

A 24 year old male patient with these lesions for 3 weeks. What is your diagnosis?