Hands and Fingers



Hands and Fingers





OVERVIEW

The hands and fingers are the workhorses of the body, constantly in contact with, and exposed regularly to the external environment in all seasons. Sun exposure, soaps, and other harsh contactants are daily insults and irritants. Fortunately, the palmar surfaces are adapted with a thick stratum corneum that is a much more resilient barrier than the stratum corneum on the dorsal surfaces; thus, the palms experience less frequent episodes of irritant and allergic contact dermatitis. In contrast, the dorsal surfaces are much more likely to develop both irritant and allergic contact dermatitis as well as sun-induced atypical lesions.

The fingers and periungual areas can offer hints to diagnosing autoimmune disorders such as systemic lupus erythematosus, dermatomyositis, and scleroderma.



HANDS, FINGERS, AND TOES OF YOUNG CHILDREN

Scarlet fever (SF), toxic shock syndrome (TSS), and Kawasaki disease (KD) all exhibit palmoplantar desquamation. SF and TSS are most commonly triggered by an erythrogenic exotoxin-producing strain of group A beta-hemolytic streptococci or staphylococcal species. The cause of KD is unknown.


Scarlet Fever



Distinguishing Features

During the convalescent phase of the illness, the skin of the palms and soles frequently desquamates. The desquamation may be sheet-like (Fig. 14-1, A and B).


Toxic Shock Syndrome



Distinguishing Features



  • Symptoms include erythema and edema of the palms and soles, as well as desquamation that occurs 1 to 3 weeks after the onset of illness (Fig. 14-2)


Kawasaki Disease







Figure 14-1 A and B. Streptococcal scarlet fever, desquamation.

Skin peeling from this boy’s soles (A) and palms (B) during the convalescent phase of his illness. This exuberant desquamation occurred 2 weeks after he had fever and a truncal exanthem that began as a streptococcal throat infection.






Figure 14-2 Toxic Shock Syndrome.

Desquamation of the feet and toes after toxic shock.

(Reprinted with permission from Lugo-Somolinos A, McKinley-Grant L, Goldsmith L, et al. Visual Dx: Essential Dermatology in Pigmented Skin. Wolters Kluwer; 2011.)







Figure 14-3 Kawasaki Disease (Mucocutaneous lymph node syndrome).

Edema of the hand in this child.


Distinguishing Features



  • Erythema of palms and soles, indurative edema of the hands (Fig. 14-3) and feet, followed by desquamation of the fingertips


DORSAL SURFACE OF HANDS


Granuloma Annulare



Distinguishing Features



  • Lesions are red, pink, or skin-colored firm dermal papules that most often arise on the dorsal surfaces of the hands, fingers, and feet (see Fig. 19-14), less often, on the extensor aspects of the arms and legs






    Figure 14-4 Granuloma annulare.

    Erythematous annular and arcuate (crescent-shaped), dermal papules.


  • May be individual, isolated papules or joined in annular or semiannular (arciform) plaques with central clearing (Fig. 14-4)


  • Lesions have no epidermal change (i.e., scale)


  • Centers of lesions may be slightly hyperpigmented and depressed relative to their borders


  • Generally asymptomatic; primarily a cosmetic concern


  • In adults, GA may also be found on the elbows, trunk, legs, and neck


  • Subcutaneous nodules similar to rheumatoid nodules may be seen on arms and legs


  • In the generalized form, multiple small, skin-colored, erythematous or violaceous lesions appear on the trunk and, to a lesser extent, on the limbs. The distinctive annular pattern is not always present




Phytophotodermatitis



Distinguishing Features



  • Occurs during the spring or summer following an outdoor activity, such as squeezing lemons or limes on chicken or fish while outdoor barbequing, or from contact with one of the responsible plants


  • The initial skin response resembles an exaggerated sunburn which may be accompanied by blisters (Fig. 14-5, A). The reaction typically begins within 24 hours of exposure and peaks at 48 to 72 hours


  • Postinflammatory hyperpigmentation that may last several weeks or longer typically ensues (Fig. 14-5, B)



Solar Lentigines vs Seborrheic Keratoses







Figure 14-5 A and B. Phytophotodermatitis.

A, This woman was squeezing limes for an outdoor barbecue 2 days before this blistering eruption began. B, This is the same patient 2 weeks later. Note the postinflammatory hyperpigmentation that faded shortly thereafter.






Figure 14-6 Solar Lentigines.

Small uniformly pigmented macules.







Figure 14-7 Seborrheic keratoses.

Small whitish-tan scaly, warty papules.






Figure 14-8 Actinic keratoses.

Multiple elevated rough-textured papules with white scale overlying sun damaged skin.


Actinic Keratosis vs Squamous Cell Carcinoma (See Scalp, Forehead and Temples, and Arms)







Figure 14-9 Squamous cell carcinoma.

A well-differentiated SCC with a thick hyperkeratotic surface.


PALMAR SURFACE OF HANDS


Hand Eczema



Dyshidrotic Eczema Distinguishing Features

Dyshidrotic eczema, the “wet” vesicular type, or pompholyx (the Greek word for bubble), is characterized by the following:



  • Intensely itchy, clear vesicles that are typically located on the palms and sides of the fingers; can also occur on the soles of the feet and the lateral aspects of the toes



  • Initially, the vesicles are very small and clear and resemble little bubbles (Figs. 14-10 and 14-11)


  • Later, as they dry and resolve without rupturing, they turn into golden brown vesicles and pustules (Fig. 14-12) that are most often sterile; however, secondary bacterial infection (impetiginization) may occur






Figure 14-10 Dyshidrotic eczema, pompholyx.

These are itchy, clear vesicles (“wet type” hand eczema) that are typically located on the palms and sides of the fingers.






Figure 14-11 Dyshidrotic hand eczema, pompholyx.

Vesicles on the sides of the fingers and webspace are shown here.






Figure 14-12 Dyshidrotic hand eczema, pustular.

Itchy, erythematous, vesicles, crusts, and pustules.

(Image courtesy of Mark Lebwohl, MD.)


Hyperkeratotic Hand Eczema Distinguishing Features

Hyperkeratotic, the “dry,” scaly type of hand eczema, is characterized by the following:



  • Scaly, itchy, erythematous plaques; skin surface loses flexibility and often develops painful fissures (Fig. 14-13)


  • Palms in atopic individuals may reveal hyperlinear skin markings which is analogous to lichenification (Fig. 14-14)



Palmoplantar Psoriasis



Distinguishing Features



  • Well-demarcated erythematous plaques, with or without thick scales (Fig. 14-15)


  • Less likely to itch than eczema


  • Pustular variant is much less common (Figs. 14-16 and 14-17)


  • Nails may show characteristic changes (see Fingernails)


  • Often a positive family history of psoriasis






Figure 14-15 Palmar psoriasis.

These erythematous lesions are well-demarcated and symmetrical in distribution.






Figure 14-16 Palmoplantar psoriasis/palmoplantar pustulosis.

Well-demarcated psoriatic plaques with multiple pustules.






Figure 14-17 Palmoplantar psoriasis/palmoplantar pustulosis.

“Lakes of pus” in palmoplantar psoriasis. These pustules are sterile.


Jan 8, 2023 | Posted by in Dermatology | Comments Off on Hands and Fingers

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