Association of generalized dystrophic epidermolysis bullosa with positive acetylcholinesterase and markedly elevated maternal serum and amniotic fluid alpha-fetoprotein

Cholinergic control of epidermal cohesion

The non-neuronal cholinergic system of human epidermis includes the keratinocyte (KC) acetylcholine (ACh) axis composed of the enzymes mediating ACh synthesis and degradation, and two classes of ACh receptors, the nicotinic and muscarinic ACh receptors, mediating biological effects of the cutaneous cytotransmitter ACh. Regulation of KC cell-cell and cell-matrix adhesion is one of the important biological functions of cutaneous ACh. The downstream targets of ACh effects mediated by distinct ACh receptor subtypes include both the intercellular adhesion molecules, such as classical and desmosomal cadherins, and integrins mediating KC adhesion to a substrate. The signaling pathways include activation or inhibition of kinase cascades resulting in either up- or down-regulation of the expression of cell adhesion molecules or changes in their phosphorylation status, or both. The components of the KC ACh axis are involved in cutaneous blistering in patients with autoimmune pemphigus, junctional and dystrophic forms of epidermolysis bullosa, thermal burns, and mustard-induced vesication. Recent progress with the development of antiacantholytic therapies of patients with pemphigus using cholinomimetics indicates that cholinergic drugs may be a promising approach for other cutaneous blistering disorders.

Laryngeal involvement in the Dowling-Meara variant of epidermolysis bullosa simplex with keratin mutations of severely disruptive potential

The clinical features of the Dowling-Meara variant of epidermolysis bullosa simplex (EBS-DM) can, in an infant, be indistinguishable from other severe forms of epidermolysis bullosa (EB). Two unrelated infants with no family history of skin disease are described who, within hours of birth, developed extensive blistering of skin and oral mucosae and who both subsequently developed hoarse cries. Despite this superficial resemblance to other forms of EB, electron microscopy revealed a basal cell rupture and keratin aggregates characteristic of EBS-DM in the skin of both infants and in the vocal cord epithelium of one. Molecular analysis confirmed the diagnosis by identification of mis-sense point mutations in basal cell keratin genes in both cases. One patient carries a point mutation in keratin 14 (converting arginine at position 125 to histidine) and the other has a novel point mutation in keratin 5 (converting serine at position 181 to proline). Hoarseness is not a well documented feature of EBS-DM and is usually associated with junctional EB. These two patients demonstrate that the presence of a hoarse cry in an infant affected by severe EB does not necessarily indicate a poor prognosis.