Sarcoidosis:

Sarcoidosis is a multisystem granulomatous disorder of unknown aetiology. It can present as reddish brown dermal papules and nodules, especially around the eyelid margins and the rim of the nostrils. More polymorphic lesions (papules nodules and plaques) may appear on the body. It is most common in black Africans where it is often accompanied by hypo- or hyperpigmentation. Rarely it can present with a bluish red infiltrate or swelling, especially of the nose or ears, called lupus pernio. Both these types of lesion can be seen anywhere on the body but are common on the face. Erythema nodosum of the shins is sometimes seen in acute-onset sarcoidosis. Erythema nodosum is an immunological reaction and not due to sarcoid tissue infiltration. Swollen fingers from a dactylitis occur. Whilst sarcoidosis may be confined to the skin, all patients should be investigated for evidence of systemic disease
Treatment of cutaneous lesions includes very potent topical steroids (0.05% clobetasol propionate), intralesional steroids, oral steroids and occasionally methotrexate or antimalarials.

Neurofibromatosis type 1 (von Recklinghausen's disease)
Type 1 neurofibromatosis is an autosomal dominant condition with complete penetrance. It often presents in childhood with a variety of cutaneous features. Many cases are new mutations in the NF1 gene. Early signs include café-au-lait spots (brown macules, greater than 2.5 cm in diameter and more than five lesions) and axillary freckling. Lisch nodules (hyperpigmented iris hamartomas) may be seen in the eyes by slit lamp examination. Later on, fleshy skin tags and deeper soft tumours (neurofibromas) appear and they may progress to completely cover the skin causing significant cosmetic disability. Learning difficulties and skeletal dysplasias occur. A number of endocrine disorders may be rarely associated including phaeochromocytoma, acromegaly and Addison's disease.